diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 9b40ffb26a2..dbb22127e82 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -12,11 +12,11 @@ class ApplicationController < ActionController::Base
   include WorkhorseHelper
   include EnforcesTwoFactorAuthentication
   include WithPerformanceBar
+  include SessionlessAuthentication
   # this can be removed after switching to rails 5
   # https://gitlab.com/gitlab-org/gitlab-ce/issues/51908
   include InvalidUTF8ErrorHandler unless Gitlab.rails5?
 
-  before_action :authenticate_sessionless_user!
   before_action :authenticate_user!
   before_action :enforce_terms!, if: :should_enforce_terms?
   before_action :validate_user_service_ticket!
@@ -153,13 +153,6 @@ class ApplicationController < ActionController::Base
     end
   end
 
-  # This filter handles personal access tokens, and atom requests with rss tokens
-  def authenticate_sessionless_user!
-    user = Gitlab::Auth::RequestAuthenticator.new(request).find_sessionless_user
-
-    sessionless_sign_in(user) if user
-  end
-
   def log_exception(exception)
     Raven.capture_exception(exception) if sentry_enabled?
 
@@ -426,25 +419,11 @@ class ApplicationController < ActionController::Base
     Gitlab::I18n.with_user_locale(current_user, &block)
   end
 
-  def sessionless_sign_in(user)
-    if user && can?(user, :log_in)
-      # Notice we are passing store false, so the user is not
-      # actually stored in the session and a token is needed
-      # for every request. If you want the token to work as a
-      # sign in token, you can simply remove store: false.
-      sign_in(user, store: false, message: :sessionless_sign_in)
-    end
-  end
-
   def set_page_title_header
     # Per https://tools.ietf.org/html/rfc5987, headers need to be ISO-8859-1, not UTF-8
     response.headers['Page-Title'] = URI.escape(page_title('GitLab'))
   end
 
-  def sessionless_user?
-    current_user && !session.keys.include?('warden.user.user.key')
-  end
-
   def peek_request?
     request.path.start_with?('/-/peek')
   end
diff --git a/app/controllers/concerns/sessionless_authentication.rb b/app/controllers/concerns/sessionless_authentication.rb
new file mode 100644
index 00000000000..590eefc6dab
--- /dev/null
+++ b/app/controllers/concerns/sessionless_authentication.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# == SessionlessAuthentication
+#
+# Controller concern to handle PAT and RSS token authentication methods
+#
+module SessionlessAuthentication
+  # This filter handles personal access tokens, and atom requests with rss tokens
+  def authenticate_sessionless_user!(request_format)
+    user = Gitlab::Auth::RequestAuthenticator.new(request).find_sessionless_user(request_format)
+
+    sessionless_sign_in(user) if user
+  end
+
+  def sessionless_user?
+    current_user && !session.keys.include?('warden.user.user.key')
+  end
+
+  def sessionless_sign_in(user)
+    if user && can?(user, :log_in)
+      # Notice we are passing store false, so the user is not
+      # actually stored in the session and a token is needed
+      # for every request. If you want the token to work as a
+      # sign in token, you can simply remove store: false.
+      sign_in(user, store: false, message: :sessionless_sign_in)
+    end
+  end
+end
diff --git a/app/controllers/dashboard/projects_controller.rb b/app/controllers/dashboard/projects_controller.rb
index e9686ed8d06..57e612d89d3 100644
--- a/app/controllers/dashboard/projects_controller.rb
+++ b/app/controllers/dashboard/projects_controller.rb
@@ -4,6 +4,7 @@ class Dashboard::ProjectsController < Dashboard::ApplicationController
   include ParamsBackwardCompatibility
   include RendersMemberAccess
 
+  prepend_before_action(only: [:index]) { authenticate_sessionless_user!(:rss) }
   before_action :set_non_archived_param
   before_action :default_sorting
   skip_cross_project_access_check :index, :starred
diff --git a/app/controllers/dashboard_controller.rb b/app/controllers/dashboard_controller.rb
index 4ce9be44403..be2d9512c01 100644
--- a/app/controllers/dashboard_controller.rb
+++ b/app/controllers/dashboard_controller.rb
@@ -4,6 +4,9 @@ class DashboardController < Dashboard::ApplicationController
   include IssuesAction
   include MergeRequestsAction
 
+  prepend_before_action(only: [:issues]) { authenticate_sessionless_user!(:rss) }
+  prepend_before_action(only: [:issues_calendar]) { authenticate_sessionless_user!(:ics) }
+
   before_action :event_filter, only: :activity
   before_action :projects, only: [:issues, :merge_requests]
   before_action :set_show_full_reference, only: [:issues, :merge_requests]
diff --git a/app/controllers/graphql_controller.rb b/app/controllers/graphql_controller.rb
index a1ec144410b..6ea4758ec32 100644
--- a/app/controllers/graphql_controller.rb
+++ b/app/controllers/graphql_controller.rb
@@ -3,6 +3,7 @@
 class GraphqlController < ApplicationController
   # Unauthenticated users have access to the API for public data
   skip_before_action :authenticate_user!
+  prepend_before_action(only: [:execute]) { authenticate_sessionless_user!(:api) }
 
   before_action :check_graphql_feature_flag!
 
diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
index 062c8c4e9e1..c5d8ac2ed77 100644
--- a/app/controllers/groups_controller.rb
+++ b/app/controllers/groups_controller.rb
@@ -9,6 +9,9 @@ class GroupsController < Groups::ApplicationController
 
   respond_to :html
 
+  prepend_before_action(only: [:show, :issues]) { authenticate_sessionless_user!(:rss) }
+  prepend_before_action(only: [:issues_calendar]) { authenticate_sessionless_user!(:ics) }
+
   before_action :authenticate_user!, only: [:new, :create]
   before_action :group, except: [:index, :new, :create]
 
diff --git a/app/controllers/projects/commits_controller.rb b/app/controllers/projects/commits_controller.rb
index 84a2a461da7..8ba18aacc58 100644
--- a/app/controllers/projects/commits_controller.rb
+++ b/app/controllers/projects/commits_controller.rb
@@ -6,6 +6,7 @@ class Projects::CommitsController < Projects::ApplicationController
   include ExtractsPath
   include RendersCommits
 
+  prepend_before_action(only: [:show]) { authenticate_sessionless_user!(:rss) }
   before_action :whitelist_query_limiting, except: :commits_root
   before_action :require_non_empty_project
   before_action :assign_ref_vars, except: :commits_root
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index d6d7110355b..c6ab6b4642e 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -9,10 +9,6 @@ class Projects::IssuesController < Projects::ApplicationController
   include IssuesCalendar
   include SpammableActions
 
-  def self.authenticate_user_only_actions
-    %i[new]
-  end
-
   def self.issue_except_actions
     %i[index calendar new create bulk_update]
   end
@@ -21,7 +17,10 @@ class Projects::IssuesController < Projects::ApplicationController
     %i[index calendar]
   end
 
-  prepend_before_action :authenticate_user!, only: authenticate_user_only_actions
+  prepend_before_action(only: [:index]) { authenticate_sessionless_user!(:rss) }
+  prepend_before_action(only: [:calendar]) { authenticate_sessionless_user!(:ics) }
+  prepend_before_action :authenticate_new_issue!, only: [:new]
+  prepend_before_action :store_uri, only: [:new, :show]
 
   before_action :whitelist_query_limiting, only: [:create, :create_merge_request, :move, :bulk_update]
   before_action :check_issues_available!
@@ -232,16 +231,18 @@ class Projects::IssuesController < Projects::ApplicationController
     ] + [{ label_ids: [], assignee_ids: [] }]
   end
 
-  def authenticate_user!
+  def authenticate_new_issue!
     return if current_user
 
     notice = "Please sign in to create the new issue."
 
+    redirect_to new_user_session_path, notice: notice
+  end
+
+  def store_uri
     if request.get? && !request.xhr?
       store_location_for :user, request.fullpath
     end
-
-    redirect_to new_user_session_path, notice: notice
   end
 
   def serializer
diff --git a/app/controllers/projects/tags_controller.rb b/app/controllers/projects/tags_controller.rb
index c8442ff3592..2b28670a49b 100644
--- a/app/controllers/projects/tags_controller.rb
+++ b/app/controllers/projects/tags_controller.rb
@@ -3,6 +3,8 @@
 class Projects::TagsController < Projects::ApplicationController
   include SortingHelper
 
+  prepend_before_action(only: [:index]) { authenticate_sessionless_user!(:rss) }
+
   # Authorize
   before_action :require_non_empty_project
   before_action :authorize_download_code!
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 7f4a9f5151b..8bf93bfd68d 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -7,6 +7,8 @@ class ProjectsController < Projects::ApplicationController
   include PreviewMarkdown
   include SendFileUpload
 
+  prepend_before_action(only: [:show]) { authenticate_sessionless_user!(:rss) }
+
   before_action :whitelist_query_limiting, only: [:create]
   before_action :authenticate_user!, except: [:index, :show, :activity, :refs]
   before_action :redirect_git_extension, only: [:show]
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 5b70c69d7f4..8b040dc080e 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -14,6 +14,7 @@ class UsersController < ApplicationController
                                 calendar_activities: true
 
   skip_before_action :authenticate_user!
+  prepend_before_action(only: [:show]) { authenticate_sessionless_user!(:rss) }
   before_action :user, except: [:exists]
   before_action :authorize_read_user_profile!,
                 only: [:calendar, :calendar_activities, :groups, :projects, :contributed_projects, :snippets]
diff --git a/changelogs/unreleased/security-fix-pat-web-access.yml b/changelogs/unreleased/security-fix-pat-web-access.yml
new file mode 100644
index 00000000000..62ffb908fe5
--- /dev/null
+++ b/changelogs/unreleased/security-fix-pat-web-access.yml
@@ -0,0 +1,5 @@
+---
+title: Restrict Personal Access Tokens to API scope on web requests
+merge_request:
+author:
+type: security
diff --git a/config/initializers/rack_attack_global.rb b/config/initializers/rack_attack_global.rb
index 45963831c41..86cb930eca9 100644
--- a/config/initializers/rack_attack_global.rb
+++ b/config/initializers/rack_attack_global.rb
@@ -33,22 +33,22 @@ class Rack::Attack
   throttle('throttle_authenticated_api', Gitlab::Throttle.authenticated_api_options) do |req|
     Gitlab::Throttle.settings.throttle_authenticated_api_enabled &&
       req.api_request? &&
-      req.authenticated_user_id
+      req.authenticated_user_id([:api])
   end
 
   throttle('throttle_authenticated_web', Gitlab::Throttle.authenticated_web_options) do |req|
     Gitlab::Throttle.settings.throttle_authenticated_web_enabled &&
       req.web_request? &&
-      req.authenticated_user_id
+      req.authenticated_user_id([:api, :rss, :ics])
   end
 
   class Request
     def unauthenticated?
-      !authenticated_user_id
+      !authenticated_user_id([:api, :rss, :ics])
     end
 
-    def authenticated_user_id
-      Gitlab::Auth::RequestAuthenticator.new(self).user&.id
+    def authenticated_user_id(request_formats)
+      Gitlab::Auth::RequestAuthenticator.new(self).user(request_formats)&.id
     end
 
     def api_request?
diff --git a/lib/gitlab/auth/request_authenticator.rb b/lib/gitlab/auth/request_authenticator.rb
index cb9f2582936..176766d1a8b 100644
--- a/lib/gitlab/auth/request_authenticator.rb
+++ b/lib/gitlab/auth/request_authenticator.rb
@@ -13,12 +13,18 @@ module Gitlab
         @request = request
       end
 
-      def user
-        find_sessionless_user || find_user_from_warden
+      def user(request_formats)
+        request_formats.each do |format|
+          user = find_sessionless_user(format)
+
+          return user if user
+        end
+
+        find_user_from_warden
       end
 
-      def find_sessionless_user
-        find_user_from_access_token || find_user_from_feed_token
+      def find_sessionless_user(request_format)
+        find_user_from_web_access_token(request_format) || find_user_from_feed_token(request_format)
       rescue Gitlab::Auth::AuthenticationError
         nil
       end
diff --git a/lib/gitlab/auth/user_auth_finders.rb b/lib/gitlab/auth/user_auth_finders.rb
index c304adc64db..adba9084845 100644
--- a/lib/gitlab/auth/user_auth_finders.rb
+++ b/lib/gitlab/auth/user_auth_finders.rb
@@ -27,8 +27,8 @@ module Gitlab
         current_request.env['warden']&.authenticate if verified_request?
       end
 
-      def find_user_from_feed_token
-        return unless rss_request? || ics_request?
+      def find_user_from_feed_token(request_format)
+        return unless valid_rss_format?(request_format)
 
         # NOTE: feed_token was renamed from rss_token but both needs to be supported because
         #       users might have already added the feed to their RSS reader before the rename
@@ -38,6 +38,17 @@ module Gitlab
         User.find_by_feed_token(token) || raise(UnauthorizedError)
       end
 
+      # We only allow Private Access Tokens with `api` scope to be used by web
+      # requests on RSS feeds or ICS files for backwards compatibility.
+      # It is also used by GraphQL/API requests.
+      def find_user_from_web_access_token(request_format)
+        return unless access_token && valid_web_access_format?(request_format)
+
+        validate_access_token!(scopes: [:api])
+
+        access_token.user || raise(UnauthorizedError)
+      end
+
       def find_user_from_access_token
         return unless access_token
 
@@ -109,6 +120,26 @@ module Gitlab
         @current_request ||= ensure_action_dispatch_request(request)
       end
 
+      def valid_web_access_format?(request_format)
+        case request_format
+        when :rss
+          rss_request?
+        when :ics
+          ics_request?
+        when :api
+          api_request?
+        end
+      end
+
+      def valid_rss_format?(request_format)
+        case request_format
+        when :rss
+          rss_request?
+        when :ics
+          ics_request?
+        end
+      end
+
       def rss_request?
         current_request.path.ends_with?('.atom') || current_request.format.atom?
       end
@@ -116,6 +147,10 @@ module Gitlab
       def ics_request?
         current_request.path.ends_with?('.ics') || current_request.format.ics?
       end
+
+      def api_request?
+        current_request.path.starts_with?("/api/")
+      end
     end
   end
 end
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index efc3ce74627..1b585bcd4c6 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -107,59 +107,6 @@ describe ApplicationController do
     end
   end
 
-  describe "#authenticate_user_from_personal_access_token!" do
-    before do
-      stub_authentication_activity_metrics(debug: false)
-    end
-
-    controller(described_class) do
-      def index
-        render text: 'authenticated'
-      end
-    end
-
-    let(:personal_access_token) { create(:personal_access_token, user: user) }
-
-    context "when the 'personal_access_token' param is populated with the personal access token" do
-      it "logs the user in" do
-        expect(authentication_metrics)
-          .to increment(:user_authenticated_counter)
-          .and increment(:user_session_override_counter)
-          .and increment(:user_sessionless_authentication_counter)
-
-        get :index, private_token: personal_access_token.token
-
-        expect(response).to have_gitlab_http_status(200)
-        expect(response.body).to eq('authenticated')
-      end
-    end
-
-    context "when the 'PERSONAL_ACCESS_TOKEN' header is populated with the personal access token" do
-      it "logs the user in" do
-        expect(authentication_metrics)
-          .to increment(:user_authenticated_counter)
-          .and increment(:user_session_override_counter)
-          .and increment(:user_sessionless_authentication_counter)
-
-        @request.headers["PRIVATE-TOKEN"] = personal_access_token.token
-        get :index
-
-        expect(response).to have_gitlab_http_status(200)
-        expect(response.body).to eq('authenticated')
-      end
-    end
-
-    it "doesn't log the user in otherwise" do
-      expect(authentication_metrics)
-        .to increment(:user_unauthenticated_counter)
-
-      get :index, private_token: "token"
-
-      expect(response.status).not_to eq(200)
-      expect(response.body).not_to eq('authenticated')
-    end
-  end
-
   describe 'session expiration' do
     controller(described_class) do
       # The anonymous controller will report 401 and fail to run any actions.
@@ -224,74 +171,6 @@ describe ApplicationController do
     end
   end
 
-  describe '#authenticate_sessionless_user!' do
-    before do
-      stub_authentication_activity_metrics(debug: false)
-    end
-
-    describe 'authenticating a user from a feed token' do
-      controller(described_class) do
-        def index
-          render text: 'authenticated'
-        end
-      end
-
-      context "when the 'feed_token' param is populated with the feed token" do
-        context 'when the request format is atom' do
-          it "logs the user in" do
-            expect(authentication_metrics)
-              .to increment(:user_authenticated_counter)
-              .and increment(:user_session_override_counter)
-              .and increment(:user_sessionless_authentication_counter)
-
-            get :index, feed_token: user.feed_token, format: :atom
-
-            expect(response).to have_gitlab_http_status 200
-            expect(response.body).to eq 'authenticated'
-          end
-        end
-
-        context 'when the request format is ics' do
-          it "logs the user in" do
-            expect(authentication_metrics)
-              .to increment(:user_authenticated_counter)
-              .and increment(:user_session_override_counter)
-              .and increment(:user_sessionless_authentication_counter)
-
-            get :index, feed_token: user.feed_token, format: :ics
-
-            expect(response).to have_gitlab_http_status 200
-            expect(response.body).to eq 'authenticated'
-          end
-        end
-
-        context 'when the request format is neither atom nor ics' do
-          it "doesn't log the user in" do
-            expect(authentication_metrics)
-              .to increment(:user_unauthenticated_counter)
-
-            get :index, feed_token: user.feed_token
-
-            expect(response.status).not_to have_gitlab_http_status 200
-            expect(response.body).not_to eq 'authenticated'
-          end
-        end
-      end
-
-      context "when the 'feed_token' param is populated with an invalid feed token" do
-        it "doesn't log the user" do
-          expect(authentication_metrics)
-            .to increment(:user_unauthenticated_counter)
-
-          get :index, feed_token: 'token', format: :atom
-
-          expect(response.status).not_to eq 200
-          expect(response.body).not_to eq 'authenticated'
-        end
-      end
-    end
-  end
-
   describe '#route_not_found' do
     it 'renders 404 if authenticated' do
       allow(controller).to receive(:current_user).and_return(user)
@@ -557,36 +436,6 @@ describe ApplicationController do
 
         expect(response).to have_gitlab_http_status(200)
       end
-
-      context 'for sessionless users' do
-        render_views
-
-        before do
-          sign_out user
-        end
-
-        it 'renders a 403 when the sessionless user did not accept the terms' do
-          get :index, feed_token: user.feed_token, format: :atom
-
-          expect(response).to have_gitlab_http_status(403)
-        end
-
-        it 'renders the error message when the format was html' do
-          get :index,
-              private_token: create(:personal_access_token, user: user).token,
-              format: :html
-
-          expect(response.body).to have_content /accept the terms of service/i
-        end
-
-        it 'renders a 200 when the sessionless user accepted the terms' do
-          accept_terms(user)
-
-          get :index, feed_token: user.feed_token, format: :atom
-
-          expect(response).to have_gitlab_http_status(200)
-        end
-      end
     end
   end
 
diff --git a/spec/controllers/dashboard/projects_controller_spec.rb b/spec/controllers/dashboard/projects_controller_spec.rb
new file mode 100644
index 00000000000..2975205e09c
--- /dev/null
+++ b/spec/controllers/dashboard/projects_controller_spec.rb
@@ -0,0 +1,5 @@
+require 'spec_helper'
+
+describe Dashboard::ProjectsController do
+  it_behaves_like 'authenticates sessionless user', :index, :atom
+end
diff --git a/spec/controllers/dashboard_controller_spec.rb b/spec/controllers/dashboard_controller_spec.rb
index 187542ba30c..c857a78d5e8 100644
--- a/spec/controllers/dashboard_controller_spec.rb
+++ b/spec/controllers/dashboard_controller_spec.rb
@@ -1,21 +1,26 @@
 require 'spec_helper'
 
 describe DashboardController do
-  let(:user) { create(:user) }
-  let(:project) { create(:project) }
+  context 'signed in' do
+    let(:user) { create(:user) }
+    let(:project) { create(:project) }
 
-  before do
-    project.add_maintainer(user)
-    sign_in(user)
+    before do
+      project.add_maintainer(user)
+      sign_in(user)
+    end
+
+    describe 'GET issues' do
+      it_behaves_like 'issuables list meta-data', :issue, :issues
+      it_behaves_like 'issuables requiring filter', :issues
+    end
+
+    describe 'GET merge requests' do
+      it_behaves_like 'issuables list meta-data', :merge_request, :merge_requests
+      it_behaves_like 'issuables requiring filter', :merge_requests
+    end
   end
 
-  describe 'GET issues' do
-    it_behaves_like 'issuables list meta-data', :issue, :issues
-    it_behaves_like 'issuables requiring filter', :issues
-  end
-
-  describe 'GET merge requests' do
-    it_behaves_like 'issuables list meta-data', :merge_request, :merge_requests
-    it_behaves_like 'issuables requiring filter', :merge_requests
-  end
+  it_behaves_like 'authenticates sessionless user', :issues, :atom, author_id: User.first
+  it_behaves_like 'authenticates sessionless user', :issues_calendar, :ics
 end
diff --git a/spec/controllers/graphql_controller_spec.rb b/spec/controllers/graphql_controller_spec.rb
index 1449036e148..949ad532365 100644
--- a/spec/controllers/graphql_controller_spec.rb
+++ b/spec/controllers/graphql_controller_spec.rb
@@ -52,15 +52,58 @@ describe GraphqlController do
     end
   end
 
+  context 'token authentication' do
+    before do
+      stub_authentication_activity_metrics(debug: false)
+    end
+
+    let(:user) { create(:user, username: 'Simon') }
+    let(:personal_access_token) { create(:personal_access_token, user: user) }
+
+    context "when the 'personal_access_token' param is populated with the personal access token" do
+      it 'logs the user in' do
+        expect(authentication_metrics)
+          .to increment(:user_authenticated_counter)
+                .and increment(:user_session_override_counter)
+                       .and increment(:user_sessionless_authentication_counter)
+
+        run_test_query!(private_token: personal_access_token.token)
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(query_response).to eq('echo' => '"Simon" says: test success')
+      end
+    end
+
+    context 'when the personal access token has no api scope' do
+      it 'does not log the user in' do
+        personal_access_token.update(scopes: [:read_user])
+
+        run_test_query!(private_token: personal_access_token.token)
+
+        expect(response).to have_gitlab_http_status(200)
+
+        expect(query_response).to eq('echo' => 'nil says: test success')
+      end
+    end
+
+    context 'without token' do
+      it 'shows public data' do
+        run_test_query!
+
+        expect(query_response).to eq('echo' => 'nil says: test success')
+      end
+    end
+  end
+
   # Chosen to exercise all the moving parts in GraphqlController#execute
-  def run_test_query!(variables: { 'text' => 'test success' })
+  def run_test_query!(variables: { 'text' => 'test success' }, private_token: nil)
     query = <<~QUERY
       query Echo($text: String) {
         echo(text: $text)
       }
     QUERY
 
-    post :execute, query: query, operationName: 'Echo', variables: variables
+    post :execute, query: query, operationName: 'Echo', variables: variables, private_token: private_token
   end
 
   def query_response
diff --git a/spec/controllers/groups_controller_spec.rb b/spec/controllers/groups_controller_spec.rb
index 4de61b65f71..f6c85102830 100644
--- a/spec/controllers/groups_controller_spec.rb
+++ b/spec/controllers/groups_controller_spec.rb
@@ -606,4 +606,24 @@ describe GroupsController do
       end
     end
   end
+
+  context 'token authentication' do
+    it_behaves_like 'authenticates sessionless user', :show, :atom, public: true do
+      before do
+        default_params.merge!(id: group)
+      end
+    end
+
+    it_behaves_like 'authenticates sessionless user', :issues, :atom, public: true do
+      before do
+        default_params.merge!(id: group, author_id: user.id)
+      end
+    end
+
+    it_behaves_like 'authenticates sessionless user', :issues_calendar, :ics, public: true do
+      before do
+        default_params.merge!(id: group)
+      end
+    end
+  end
 end
diff --git a/spec/controllers/projects/commits_controller_spec.rb b/spec/controllers/projects/commits_controller_spec.rb
index a43bdd3ea80..5c72dab698c 100644
--- a/spec/controllers/projects/commits_controller_spec.rb
+++ b/spec/controllers/projects/commits_controller_spec.rb
@@ -5,87 +5,115 @@ describe Projects::CommitsController do
   let(:user) { create(:user) }
 
   before do
-    sign_in(user)
     project.add_maintainer(user)
   end
 
-  describe "GET commits_root" do
-    context "no ref is provided" do
-      it 'should redirect to the default branch of the project' do
-        get(:commits_root,
-            namespace_id: project.namespace,
-            project_id: project)
+  context 'signed in' do
+    before do
+      sign_in(user)
+    end
 
-        expect(response).to redirect_to project_commits_path(project)
+    describe "GET commits_root" do
+      context "no ref is provided" do
+        it 'should redirect to the default branch of the project' do
+          get(:commits_root,
+              namespace_id: project.namespace,
+              project_id: project)
+
+          expect(response).to redirect_to project_commits_path(project)
+        end
+      end
+    end
+
+    describe "GET show" do
+      render_views
+
+      context 'with file path' do
+        before do
+          get(:show,
+              namespace_id: project.namespace,
+              project_id: project,
+              id: id)
+        end
+
+        context "valid branch, valid file" do
+          let(:id) { 'master/README.md' }
+
+          it { is_expected.to respond_with(:success) }
+        end
+
+        context "valid branch, invalid file" do
+          let(:id) { 'master/invalid-path.rb' }
+
+          it { is_expected.to respond_with(:not_found) }
+        end
+
+        context "invalid branch, valid file" do
+          let(:id) { 'invalid-branch/README.md' }
+
+          it { is_expected.to respond_with(:not_found) }
+        end
+      end
+
+      context "when the ref name ends in .atom" do
+        context "when the ref does not exist with the suffix" do
+          before do
+            get(:show,
+                namespace_id: project.namespace,
+                project_id: project,
+                id: "master.atom")
+          end
+
+          it "renders as atom" do
+            expect(response).to be_success
+            expect(response.content_type).to eq('application/atom+xml')
+          end
+
+          it 'renders summary with type=html' do
+            expect(response.body).to include('<summary type="html">')
+          end
+        end
+
+        context "when the ref exists with the suffix" do
+          before do
+            commit = project.repository.commit('master')
+
+            allow_any_instance_of(Repository).to receive(:commit).and_call_original
+            allow_any_instance_of(Repository).to receive(:commit).with('master.atom').and_return(commit)
+
+            get(:show,
+                namespace_id: project.namespace,
+                project_id: project,
+                id: "master.atom")
+          end
+
+          it "renders as HTML" do
+            expect(response).to be_success
+            expect(response.content_type).to eq('text/html')
+          end
+        end
       end
     end
   end
 
-  describe "GET show" do
-    render_views
+  context 'token authentication' do
+    context 'public project' do
+      it_behaves_like 'authenticates sessionless user', :show, :atom, public: true do
+        before do
+          public_project = create(:project, :repository, :public)
 
-    context 'with file path' do
-      before do
-        get(:show,
-            namespace_id: project.namespace,
-            project_id: project,
-            id: id)
-      end
-
-      context "valid branch, valid file" do
-        let(:id) { 'master/README.md' }
-
-        it { is_expected.to respond_with(:success) }
-      end
-
-      context "valid branch, invalid file" do
-        let(:id) { 'master/invalid-path.rb' }
-
-        it { is_expected.to respond_with(:not_found) }
-      end
-
-      context "invalid branch, valid file" do
-        let(:id) { 'invalid-branch/README.md' }
-
-        it { is_expected.to respond_with(:not_found) }
+          default_params.merge!(namespace_id: public_project.namespace, project_id: public_project, id: "master.atom")
+        end
       end
     end
 
-    context "when the ref name ends in .atom" do
-      context "when the ref does not exist with the suffix" do
+    context 'private project' do
+      it_behaves_like 'authenticates sessionless user', :show, :atom, public: false do
         before do
-          get(:show,
-              namespace_id: project.namespace,
-              project_id: project,
-              id: "master.atom")
-        end
+          private_project = create(:project, :repository, :private)
+          private_project.add_maintainer(user)
 
-        it "renders as atom" do
-          expect(response).to be_success
-          expect(response.content_type).to eq('application/atom+xml')
-        end
-
-        it 'renders summary with type=html' do
-          expect(response.body).to include('<summary type="html">')
-        end
-      end
-
-      context "when the ref exists with the suffix" do
-        before do
-          commit = project.repository.commit('master')
-
-          allow_any_instance_of(Repository).to receive(:commit).and_call_original
-          allow_any_instance_of(Repository).to receive(:commit).with('master.atom').and_return(commit)
-
-          get(:show,
-              namespace_id: project.namespace,
-              project_id: project,
-              id: "master.atom")
-        end
-
-        it "renders as HTML" do
-          expect(response).to be_success
-          expect(response.content_type).to eq('text/html')
+          default_params.merge!(namespace_id: private_project.namespace, project_id: private_project, id: "master.atom")
         end
       end
     end
diff --git a/spec/controllers/projects/issues_controller_spec.rb b/spec/controllers/projects/issues_controller_spec.rb
index 80138183c07..02930edbf72 100644
--- a/spec/controllers/projects/issues_controller_spec.rb
+++ b/spec/controllers/projects/issues_controller_spec.rb
@@ -1068,4 +1068,40 @@ describe Projects::IssuesController do
       end
     end
   end
+
+  context 'private project with token authentication' do
+    let(:private_project) { create(:project, :private) }
+
+    it_behaves_like 'authenticates sessionless user', :index, :atom do
+      before do
+        default_params.merge!(project_id: private_project, namespace_id: private_project.namespace)
+
+        private_project.add_maintainer(user)
+      end
+    end
+
+    it_behaves_like 'authenticates sessionless user', :calendar, :ics do
+      before do
+        default_params.merge!(project_id: private_project, namespace_id: private_project.namespace)
+
+        private_project.add_maintainer(user)
+      end
+    end
+  end
+
+  context 'public project with token authentication' do
+    let(:public_project) { create(:project, :public) }
+
+    it_behaves_like 'authenticates sessionless user', :index, :atom, public: true do
+      before do
+        default_params.merge!(project_id: public_project, namespace_id: public_project.namespace)
+      end
+    end
+
+    it_behaves_like 'authenticates sessionless user', :calendar, :ics, public: true do
+      before do
+        default_params.merge!(project_id: public_project, namespace_id: public_project.namespace)
+      end
+    end
+  end
 end
diff --git a/spec/controllers/projects/tags_controller_spec.rb b/spec/controllers/projects/tags_controller_spec.rb
index c48f41ca12e..6fbf75d0259 100644
--- a/spec/controllers/projects/tags_controller_spec.rb
+++ b/spec/controllers/projects/tags_controller_spec.rb
@@ -35,4 +35,26 @@ describe Projects::TagsController do
       it { is_expected.to respond_with(:not_found) }
     end
   end
+
+  context 'private project with token authentication' do
+    let(:private_project) { create(:project, :repository, :private) }
+
+    it_behaves_like 'authenticates sessionless user', :index, :atom do
+      before do
+        default_params.merge!(project_id: private_project, namespace_id: private_project.namespace)
+
+        private_project.add_maintainer(user)
+      end
+    end
+  end
+
+  context 'public project with token authentication' do
+    let(:public_project) { create(:project, :repository, :public) }
+
+    it_behaves_like 'authenticates sessionless user', :index, :atom, public: true do
+      before do
+        default_params.merge!(project_id: public_project, namespace_id: public_project.namespace)
+      end
+    end
+  end
 end
diff --git a/spec/controllers/projects_controller_spec.rb b/spec/controllers/projects_controller_spec.rb
index 3bc9cbe64c5..7849bec4762 100644
--- a/spec/controllers/projects_controller_spec.rb
+++ b/spec/controllers/projects_controller_spec.rb
@@ -882,6 +882,28 @@ describe ProjectsController do
     end
   end
 
+  context 'private project with token authentication' do
+    let(:private_project) { create(:project, :private) }
+
+    it_behaves_like 'authenticates sessionless user', :show, :atom do
+      before do
+        default_params.merge!(id: private_project, namespace_id: private_project.namespace)
+
+        private_project.add_maintainer(user)
+      end
+    end
+  end
+
+  context 'public project with token authentication' do
+    let(:public_project) { create(:project, :public) }
+
+    it_behaves_like 'authenticates sessionless user', :show, :atom, public: true do
+      before do
+        default_params.merge!(id: public_project, namespace_id: public_project.namespace)
+      end
+    end
+  end
+
   def project_moved_message(redirect_route, project)
     "Project '#{redirect_route.path}' was moved to '#{project.full_path}'. Please update any links and bookmarks that may still have the old path."
   end
diff --git a/spec/controllers/users_controller_spec.rb b/spec/controllers/users_controller_spec.rb
index 071f96a729e..fe438e71e9e 100644
--- a/spec/controllers/users_controller_spec.rb
+++ b/spec/controllers/users_controller_spec.rb
@@ -395,6 +395,14 @@ describe UsersController do
     end
   end
 
+  context 'token authentication' do
+    it_behaves_like 'authenticates sessionless user', :show, :atom, public: true do
+      before do
+        default_params.merge!(username: user.username)
+      end
+    end
+  end
+
   def user_moved_message(redirect_route, user)
     "User '#{redirect_route.path}' was moved to '#{user.full_path}'. Please update any links and bookmarks that may still have the old path."
   end
diff --git a/spec/lib/gitlab/auth/request_authenticator_spec.rb b/spec/lib/gitlab/auth/request_authenticator_spec.rb
index 242ab4a91dd..3d979132880 100644
--- a/spec/lib/gitlab/auth/request_authenticator_spec.rb
+++ b/spec/lib/gitlab/auth/request_authenticator_spec.rb
@@ -19,17 +19,17 @@ describe Gitlab::Auth::RequestAuthenticator do
       allow_any_instance_of(described_class).to receive(:find_sessionless_user).and_return(sessionless_user)
       allow_any_instance_of(described_class).to receive(:find_user_from_warden).and_return(session_user)
 
-      expect(subject.user).to eq sessionless_user
+      expect(subject.user([:api])).to eq sessionless_user
     end
 
     it 'returns session user if no sessionless user found' do
       allow_any_instance_of(described_class).to receive(:find_user_from_warden).and_return(session_user)
 
-      expect(subject.user).to eq session_user
+      expect(subject.user([:api])).to eq session_user
     end
 
     it 'returns nil if no user found' do
-      expect(subject.user).to be_blank
+      expect(subject.user([:api])).to be_blank
     end
 
     it 'bubbles up exceptions' do
@@ -42,26 +42,26 @@ describe Gitlab::Auth::RequestAuthenticator do
     let!(:feed_token_user) { build(:user) }
 
     it 'returns access_token user first' do
-      allow_any_instance_of(described_class).to receive(:find_user_from_access_token).and_return(access_token_user)
+      allow_any_instance_of(described_class).to receive(:find_user_from_web_access_token).and_return(access_token_user)
       allow_any_instance_of(described_class).to receive(:find_user_from_feed_token).and_return(feed_token_user)
 
-      expect(subject.find_sessionless_user).to eq access_token_user
+      expect(subject.find_sessionless_user([:api])).to eq access_token_user
     end
 
     it 'returns feed_token user if no access_token user found' do
       allow_any_instance_of(described_class).to receive(:find_user_from_feed_token).and_return(feed_token_user)
 
-      expect(subject.find_sessionless_user).to eq feed_token_user
+      expect(subject.find_sessionless_user([:api])).to eq feed_token_user
     end
 
     it 'returns nil if no user found' do
-      expect(subject.find_sessionless_user).to be_blank
+      expect(subject.find_sessionless_user([:api])).to be_blank
     end
 
     it 'rescue Gitlab::Auth::AuthenticationError exceptions' do
-      allow_any_instance_of(described_class).to receive(:find_user_from_access_token).and_raise(Gitlab::Auth::UnauthorizedError)
+      allow_any_instance_of(described_class).to receive(:find_user_from_web_access_token).and_raise(Gitlab::Auth::UnauthorizedError)
 
-      expect(subject.find_sessionless_user).to be_blank
+      expect(subject.find_sessionless_user([:api])).to be_blank
     end
   end
 end
diff --git a/spec/lib/gitlab/auth/user_auth_finders_spec.rb b/spec/lib/gitlab/auth/user_auth_finders_spec.rb
index 454ad1589b9..5d3fbba264f 100644
--- a/spec/lib/gitlab/auth/user_auth_finders_spec.rb
+++ b/spec/lib/gitlab/auth/user_auth_finders_spec.rb
@@ -9,7 +9,7 @@ describe Gitlab::Auth::UserAuthFinders do
       'rack.input' => ''
     }
   end
-  let(:request) { Rack::Request.new(env)}
+  let(:request) { Rack::Request.new(env) }
 
   def set_param(key, value)
     request.update_param(key, value)
@@ -49,6 +49,7 @@ describe Gitlab::Auth::UserAuthFinders do
   describe '#find_user_from_feed_token' do
     context 'when the request format is atom' do
       before do
+        env['SCRIPT_NAME'] = 'url.atom'
         env['HTTP_ACCEPT'] = 'application/atom+xml'
       end
 
@@ -56,17 +57,17 @@ describe Gitlab::Auth::UserAuthFinders do
         it 'returns user if valid feed_token' do
           set_param(:feed_token, user.feed_token)
 
-          expect(find_user_from_feed_token).to eq user
+          expect(find_user_from_feed_token(:rss)).to eq user
         end
 
         it 'returns nil if feed_token is blank' do
-          expect(find_user_from_feed_token).to be_nil
+          expect(find_user_from_feed_token(:rss)).to be_nil
         end
 
         it 'returns exception if invalid feed_token' do
           set_param(:feed_token, 'invalid_token')
 
-          expect { find_user_from_feed_token }.to raise_error(Gitlab::Auth::UnauthorizedError)
+          expect { find_user_from_feed_token(:rss) }.to raise_error(Gitlab::Auth::UnauthorizedError)
         end
       end
 
@@ -74,34 +75,38 @@ describe Gitlab::Auth::UserAuthFinders do
         it 'returns user if valid rssd_token' do
           set_param(:rss_token, user.feed_token)
 
-          expect(find_user_from_feed_token).to eq user
+          expect(find_user_from_feed_token(:rss)).to eq user
         end
 
         it 'returns nil if rss_token is blank' do
-          expect(find_user_from_feed_token).to be_nil
+          expect(find_user_from_feed_token(:rss)).to be_nil
         end
 
         it 'returns exception if invalid rss_token' do
           set_param(:rss_token, 'invalid_token')
 
-          expect { find_user_from_feed_token }.to raise_error(Gitlab::Auth::UnauthorizedError)
+          expect { find_user_from_feed_token(:rss) }.to raise_error(Gitlab::Auth::UnauthorizedError)
         end
       end
     end
 
     context 'when the request format is not atom' do
       it 'returns nil' do
+        env['SCRIPT_NAME'] = 'json'
+
         set_param(:feed_token, user.feed_token)
 
-        expect(find_user_from_feed_token).to be_nil
+        expect(find_user_from_feed_token(:rss)).to be_nil
       end
     end
 
     context 'when the request format is empty' do
       it 'the method call does not modify the original value' do
+        env['SCRIPT_NAME'] = 'url.atom'
+
         env.delete('action_dispatch.request.formats')
 
-        find_user_from_feed_token
+        find_user_from_feed_token(:rss)
 
         expect(env['action_dispatch.request.formats']).to be_nil
       end
@@ -111,8 +116,12 @@ describe Gitlab::Auth::UserAuthFinders do
   describe '#find_user_from_access_token' do
     let(:personal_access_token) { create(:personal_access_token, user: user) }
 
+    before do
+      env['SCRIPT_NAME'] = 'url.atom'
+    end
+
     it 'returns nil if no access_token present' do
-      expect(find_personal_access_token).to be_nil
+      expect(find_user_from_access_token).to be_nil
     end
 
     context 'when validate_access_token! returns valid' do
@@ -131,9 +140,59 @@ describe Gitlab::Auth::UserAuthFinders do
     end
   end
 
+  describe '#find_user_from_web_access_token' do
+    let(:personal_access_token) { create(:personal_access_token, user: user) }
+
+    before do
+      env[Gitlab::Auth::UserAuthFinders::PRIVATE_TOKEN_HEADER] = personal_access_token.token
+    end
+
+    it 'returns exception if token has no user' do
+      allow_any_instance_of(PersonalAccessToken).to receive(:user).and_return(nil)
+
+      expect { find_user_from_access_token }.to raise_error(Gitlab::Auth::UnauthorizedError)
+    end
+
+    context 'no feed or API requests' do
+      it 'returns nil if the request is not RSS' do
+        expect(find_user_from_web_access_token(:rss)).to be_nil
+      end
+
+      it 'returns nil if the request is not ICS' do
+        expect(find_user_from_web_access_token(:ics)).to be_nil
+      end
+
+      it 'returns nil if the request is not API' do
+        expect(find_user_from_web_access_token(:api)).to be_nil
+      end
+    end
+
+    it 'returns the user for RSS requests' do
+      env['SCRIPT_NAME'] = 'url.atom'
+
+      expect(find_user_from_web_access_token(:rss)).to eq(user)
+    end
+
+    it 'returns the user for ICS requests' do
+      env['SCRIPT_NAME'] = 'url.ics'
+
+      expect(find_user_from_web_access_token(:ics)).to eq(user)
+    end
+
+    it 'returns the user for API requests' do
+      env['SCRIPT_NAME'] = '/api/endpoint'
+
+      expect(find_user_from_web_access_token(:api)).to eq(user)
+    end
+  end
+
   describe '#find_personal_access_token' do
     let(:personal_access_token) { create(:personal_access_token, user: user) }
 
+    before do
+      env['SCRIPT_NAME'] = 'url.atom'
+    end
+
     context 'passed as header' do
       it 'returns token if valid personal_access_token' do
         env[Gitlab::Auth::UserAuthFinders::PRIVATE_TOKEN_HEADER] = personal_access_token.token
diff --git a/spec/support/controllers/sessionless_auth_controller_shared_examples.rb b/spec/support/controllers/sessionless_auth_controller_shared_examples.rb
new file mode 100644
index 00000000000..7e4958f177a
--- /dev/null
+++ b/spec/support/controllers/sessionless_auth_controller_shared_examples.rb
@@ -0,0 +1,92 @@
+shared_examples 'authenticates sessionless user' do |path, format, params|
+  params ||= {}
+
+  before do
+    stub_authentication_activity_metrics(debug: false)
+  end
+
+  let(:user) { create(:user) }
+  let(:personal_access_token) { create(:personal_access_token, user: user) }
+  let(:default_params) { { format: format }.merge(params.except(:public) || {}) }
+
+  context "when the 'personal_access_token' param is populated with the personal access token" do
+    it 'logs the user in' do
+      expect(authentication_metrics)
+        .to increment(:user_authenticated_counter)
+              .and increment(:user_session_override_counter)
+                     .and increment(:user_sessionless_authentication_counter)
+
+      get path, default_params.merge(private_token: personal_access_token.token)
+
+      expect(response).to have_gitlab_http_status(200)
+      expect(controller.current_user).to eq(user)
+    end
+
+    it 'does not log the user in if page is public', if: params[:public] do
+      get path, default_params
+
+      expect(response).to have_gitlab_http_status(200)
+      expect(controller.current_user).to be_nil
+    end
+  end
+
+  context 'when the personal access token has no api scope', unless: params[:public] do
+    it 'does not log the user in' do
+      expect(authentication_metrics)
+        .to increment(:user_unauthenticated_counter)
+
+      personal_access_token.update(scopes: [:read_user])
+
+      get path, default_params.merge(private_token: personal_access_token.token)
+
+      expect(response).not_to have_gitlab_http_status(200)
+    end
+  end
+
+  context "when the 'PERSONAL_ACCESS_TOKEN' header is populated with the personal access token" do
+    it 'logs the user in' do
+      expect(authentication_metrics)
+        .to increment(:user_authenticated_counter)
+              .and increment(:user_session_override_counter)
+                     .and increment(:user_sessionless_authentication_counter)
+
+      @request.headers['PRIVATE-TOKEN'] = personal_access_token.token
+      get path, default_params
+
+      expect(response).to have_gitlab_http_status(200)
+    end
+  end
+
+  context "when the 'feed_token' param is populated with the feed token", if: format == :rss do
+    it "logs the user in" do
+      expect(authentication_metrics)
+        .to increment(:user_authenticated_counter)
+              .and increment(:user_session_override_counter)
+                     .and increment(:user_sessionless_authentication_counter)
+
+      get path, default_params.merge(feed_token: user.feed_token)
+
+      expect(response).to have_gitlab_http_status 200
+    end
+  end
+
+  context "when the 'feed_token' param is populated with an invalid feed token", if: format == :rss, unless: params[:public] do
+    it "logs the user" do
+      expect(authentication_metrics)
+        .to increment(:user_unauthenticated_counter)
+
+      get path, default_params.merge(feed_token: 'token')
+
+      expect(response.status).not_to eq 200
+    end
+  end
+
+  it "doesn't log the user in otherwise", unless: params[:public] do
+    expect(authentication_metrics)
+      .to increment(:user_unauthenticated_counter)
+
+    get path, default_params.merge(private_token: 'token')
+
+    expect(response.status).not_to eq(200)
+  end
+end