diff --git a/.gitlab/ci/releases.gitlab-ci.yml b/.gitlab/ci/releases.gitlab-ci.yml
index d4e0236f3a8..8ca4041e6be 100644
--- a/.gitlab/ci/releases.gitlab-ci.yml
+++ b/.gitlab/ci/releases.gitlab-ci.yml
@@ -9,7 +9,7 @@
   image: alpine:edge
   stage: sync
   before_script:
-    - apk add --no-cache --update curl bash
+    - apk add --no-cache --update curl bash jq
   after_script: []
   script:
     - bash scripts/sync-stable-branch.sh
diff --git a/CHANGELOG-EE.md b/CHANGELOG-EE.md
index dc4e390ebc8..b52bdaef27d 100644
--- a/CHANGELOG-EE.md
+++ b/CHANGELOG-EE.md
@@ -1,5 +1,13 @@
 Please view this file on the master branch, on stable branches it's out of date.
 
+## 12.6.2
+
+### Security (2 changes)
+
+- Don't publish drafts if user can't create notes.
+- Remove protected tag access when group is removed.
+
+
 ## 12.6.1
 
 - No changes.
diff --git a/app/controllers/profiles/notifications_controller.rb b/app/controllers/profiles/notifications_controller.rb
index 5f44e55f3ef..d295b64082c 100644
--- a/app/controllers/profiles/notifications_controller.rb
+++ b/app/controllers/profiles/notifications_controller.rb
@@ -11,6 +11,7 @@ class Profiles::NotificationsController < Profiles::ApplicationController
       exclude_group_ids: @group_notifications.select(:source_id)
     ).execute.map { |group| current_user.notification_settings_for(group, inherit: true) }
     @project_notifications = current_user.notification_settings.for_projects.order(:id)
+                             .select { |notification| current_user.can?(:read_project, notification.source) }
     @global_notification_setting = current_user.global_notification_setting
   end
   # rubocop: enable CodeReuse/ActiveRecord
diff --git a/app/controllers/projects/releases_controller.rb b/app/controllers/projects/releases_controller.rb
index ffe69fe97e4..d6030a9e455 100644
--- a/app/controllers/projects/releases_controller.rb
+++ b/app/controllers/projects/releases_controller.rb
@@ -10,7 +10,7 @@ class Projects::ReleasesController < Projects::ApplicationController
     push_frontend_feature_flag(:release_evidence_collection, project)
   end
   before_action :authorize_update_release!, only: %i[edit update]
-  before_action :authorize_download_code!, only: [:evidence]
+  before_action :authorize_read_release_evidence!, only: [:evidence]
 
   def index
     respond_to do |format|
@@ -47,6 +47,11 @@ class Projects::ReleasesController < Projects::ApplicationController
     access_denied! unless can?(current_user, :update_release, release)
   end
 
+  def authorize_read_release_evidence!
+    access_denied! unless Feature.enabled?(:release_evidence, project, default_enabled: true)
+    access_denied! unless can?(current_user, :read_release_evidence, release)
+  end
+
   def release
     @release ||= project.releases.find_by_tag!(sanitized_tag_name)
   end
diff --git a/app/helpers/notifications_helper.rb b/app/helpers/notifications_helper.rb
index 8855e0cdd70..9a64fe98f86 100644
--- a/app/helpers/notifications_helper.rb
+++ b/app/helpers/notifications_helper.rb
@@ -116,4 +116,8 @@ module NotificationsHelper
   def show_unsubscribe_title?(noteable)
     can?(current_user, "read_#{noteable.to_ability_name}".to_sym, noteable)
   end
+
+  def can_read_project?(project)
+    can?(current_user, :read_project, project)
+  end
 end
diff --git a/app/models/evidence.rb b/app/models/evidence.rb
index 69a00f1cb3f..55149ab0dfa 100644
--- a/app/models/evidence.rb
+++ b/app/models/evidence.rb
@@ -15,6 +15,21 @@ class Evidence < ApplicationRecord
     @milestones ||= release.milestones.includes(:issues)
   end
 
+  ##
+  # Return `summary` without sensitive information.
+  #
+  # Removing issues from summary in order to prevent leaking confidential ones.
+  # See more https://gitlab.com/gitlab-org/gitlab/issues/121930
+  def summary
+    safe_summary = read_attribute(:summary)
+
+    safe_summary.dig('release', 'milestones')&.each do |milestone|
+      milestone.delete('issues')
+    end
+
+    safe_summary
+  end
+
   private
 
   def generate_summary_and_sha
diff --git a/app/models/user.rb b/app/models/user.rb
index 18bf5ceaa0e..ee42a987939 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1327,7 +1327,7 @@ class User < ApplicationRecord
         .select('ci_runners.*')
 
       group_runners = Ci::RunnerNamespace
-        .where(namespace_id: owned_or_maintainers_groups.select(:id))
+        .where(namespace_id: owned_groups.select(:id))
         .joins(:runner)
         .select('ci_runners.*')
 
diff --git a/app/policies/release_policy.rb b/app/policies/release_policy.rb
index d7f9e5d7445..0fd1312c511 100644
--- a/app/policies/release_policy.rb
+++ b/app/policies/release_policy.rb
@@ -2,4 +2,31 @@
 
 class ReleasePolicy < BasePolicy
   delegate { @subject.project }
+
+  rule { allowed_to_read_evidence & external_authorization_service_disabled }.policy do
+    enable :read_release_evidence
+  end
+
+  ##
+  # evidence.summary includes the following entities:
+  # - Release
+  # - git-tag (Repository)
+  # - Project
+  # - Milestones
+  # - Issues
+  condition(:allowed_to_read_evidence) do
+    can?(:read_release) &&
+      can?(:download_code) &&
+      can?(:read_project) &&
+      can?(:read_milestone) &&
+      can?(:read_issue)
+  end
+
+  ##
+  # Currently, we don't support release evidence for the GitLab instances
+  # that enables external authorization services.
+  # See https://gitlab.com/gitlab-org/gitlab/issues/121930.
+  condition(:external_authorization_service_disabled) do
+    !Gitlab::ExternalAuthorization::Config.enabled?
+  end
 end
diff --git a/app/uploaders/avatar_uploader.rb b/app/uploaders/avatar_uploader.rb
index d42c9dbedf4..b79a5deb9c0 100644
--- a/app/uploaders/avatar_uploader.rb
+++ b/app/uploaders/avatar_uploader.rb
@@ -5,6 +5,9 @@ class AvatarUploader < GitlabUploader
   include RecordsUploads::Concern
   include ObjectStorage::Concern
   prepend ObjectStorage::Extension::RecordsUploads
+  include UploadTypeCheck::Concern
+
+  check_upload_type extensions: AvatarUploader::SAFE_IMAGE_EXT
 
   def exists?
     model.avatar.file && model.avatar.file.present?
diff --git a/app/uploaders/favicon_uploader.rb b/app/uploaders/favicon_uploader.rb
index a0b275b56a9..f393fdf0d84 100644
--- a/app/uploaders/favicon_uploader.rb
+++ b/app/uploaders/favicon_uploader.rb
@@ -1,8 +1,12 @@
 # frozen_string_literal: true
 
 class FaviconUploader < AttachmentUploader
+  include UploadTypeCheck::Concern
+
   EXTENSION_WHITELIST = %w[png ico].freeze
 
+  check_upload_type extensions: EXTENSION_WHITELIST
+
   def extension_whitelist
     EXTENSION_WHITELIST
   end
diff --git a/app/uploaders/upload_type_check.rb b/app/uploaders/upload_type_check.rb
new file mode 100644
index 00000000000..2837b001660
--- /dev/null
+++ b/app/uploaders/upload_type_check.rb
@@ -0,0 +1,98 @@
+# frozen_string_literal: true
+
+# Ensure that uploaded files are what they say they are for security and
+# handling purposes. The checks are not 100% reliable so we err on the side of
+# caution and allow by default, and deny when we're confident of a fail state.
+#
+# Include this concern, then call `check_upload_type` to check all
+# uploads. Attach a `mime_type` or `extensions` parameter to only check
+# specific upload types. Both parameters will be normalized to a MIME type and
+# checked against the inferred MIME type of the upload content and filename
+# extension.
+#
+# class YourUploader
+#   include UploadTypeCheck::Concern
+#   check_upload_type mime_types: ['image/png', /image\/jpe?g/]
+#
+#   # or...
+#
+#   check_upload_type extensions: ['png', 'jpg', 'jpeg']
+# end
+#
+# The mime_types parameter can accept `NilClass`, `String`, `Regexp`,
+# `Array[String, Regexp]`. This matches the CarrierWave `extension_whitelist`
+# and `content_type_whitelist` family of behavior.
+#
+# The extensions parameter can accept `NilClass`, `String`, `Array[String]`.
+module UploadTypeCheck
+  module Concern
+    extend ActiveSupport::Concern
+
+    class_methods do
+      def check_upload_type(mime_types: nil, extensions: nil)
+        define_method :check_upload_type_callback do |file|
+          magic_file = MagicFile.new(file.to_file)
+
+          # Map file extensions back to mime types.
+          if extensions
+            mime_types = Array(mime_types) +
+                         Array(extensions).map { |e| MimeMagic::EXTENSIONS[e] }
+          end
+
+          if mime_types.nil? || magic_file.matches_mime_types?(mime_types)
+            check_content_matches_extension!(magic_file)
+          end
+        end
+        before :cache, :check_upload_type_callback
+      end
+    end
+
+    def check_content_matches_extension!(magic_file)
+      return if magic_file.ambiguous_type?
+
+      if magic_file.magic_type != magic_file.ext_type
+        raise CarrierWave::IntegrityError, 'Content type does not match file extension'
+      end
+    end
+  end
+
+  # Convenience class to wrap MagicMime objects.
+  class MagicFile
+    attr_reader :file
+
+    def initialize(file)
+      @file = file
+    end
+
+    def magic_type
+      @magic_type ||= MimeMagic.by_magic(file)
+    end
+
+    def ext_type
+      @ext_type ||= MimeMagic.by_path(file.path)
+    end
+
+    def magic_type_type
+      magic_type&.type
+    end
+
+    def ext_type_type
+      ext_type&.type
+    end
+
+    def matches_mime_types?(mime_types)
+      Array(mime_types).any? do |mt|
+        magic_type_type =~ /\A#{mt}\z/ || ext_type_type =~ /\A#{mt}\z/
+      end
+    end
+
+    # - Both types unknown or text/plain.
+    # - Ambiguous magic type with text extension. Plain text file.
+    # - Text magic type with ambiguous extension. TeX file missing extension.
+    def ambiguous_type?
+      (ext_type.to_s.blank? && magic_type.to_s.blank?) ||
+      (magic_type.to_s.blank? && ext_type_type == 'text/plain') ||
+      (ext_type.to_s.blank? && magic_type_type == 'text/plain')
+    end
+  end
+end
diff --git a/app/views/sent_notifications/unsubscribe.html.haml b/app/views/sent_notifications/unsubscribe.html.haml
index 22fcfcda297..1eecbe3bc0e 100644
--- a/app/views/sent_notifications/unsubscribe.html.haml
+++ b/app/views/sent_notifications/unsubscribe.html.haml
@@ -1,13 +1,16 @@
 - noteable = @sent_notification.noteable
 - noteable_type = @sent_notification.noteable_type.titleize.downcase
 - noteable_text = show_unsubscribe_title?(noteable) ? %(#{noteable.title} (#{noteable.to_reference})) : %(#{noteable.to_reference})
-- page_title _("Unsubscribe"), noteable_text, noteable_type.pluralize, @sent_notification.project.full_name
+- show_project_path = can_read_project?(@sent_notification.project)
+- project_path = show_project_path ? @sent_notification.project.full_name : _("GitLab / Unsubscribe")
+- noteable_url = show_project_path ? url_for([@sent_notification.project.namespace.becomes(Namespace), @sent_notification.project, noteable]) : breadcrumb_title_link
+- page_title _('Unsubscribe'), noteable_text, noteable_type.pluralize, project_path
 
 %h3.page-title
   = _("Unsubscribe from %{type}") % { type: noteable_type }
 
 %p
-  - link_to_noteable_text = link_to(noteable_text, url_for([@sent_notification.project.namespace.becomes(Namespace), @sent_notification.project, noteable]))
+  - link_to_noteable_text = link_to(noteable_text, noteable_url)
   = _("Are you sure you want to unsubscribe from the %{type}: %{link_to_noteable_text}?").html_safe % { type: noteable_type, link_to_noteable_text: link_to_noteable_text }
 
 %p
diff --git a/changelogs/unreleased/ap-33785-file-integrity.yml b/changelogs/unreleased/ap-33785-file-integrity.yml
new file mode 100644
index 00000000000..36ff617a252
--- /dev/null
+++ b/changelogs/unreleased/ap-33785-file-integrity.yml
@@ -0,0 +1,5 @@
+---
+title: Ensure content matches extension on image uploads
+merge_request: 20697
+author:
+type: security
diff --git a/config/initializers/graphql.rb b/config/initializers/graphql.rb
index f1bc289f1f0..2b21c9d9729 100644
--- a/config/initializers/graphql.rb
+++ b/config/initializers/graphql.rb
@@ -5,3 +5,7 @@ GraphQL::Field.accepts_definitions(authorize: GraphQL::Define.assign_metadata_ke
 
 GraphQL::Schema::Object.accepts_definition(:authorize)
 GraphQL::Schema::Field.accepts_definition(:authorize)
+
+GitlabSchema.middleware << GraphQL::Schema::TimeoutMiddleware.new(max_seconds: ENV.fetch('GITLAB_RAILS_GRAPHQL_TIMEOUT', 30).to_i) do |timeout_error, query|
+  Gitlab::GraphqlLogger.error(message: timeout_error.to_s, query: query.query_string, query_variables: query.provided_variables)
+end
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index a86fb44caa1..0240fc1539f 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -1363,7 +1363,7 @@ module API
       expose :author, using: Entities::UserBasic, if: -> (release, _) { release.author.present? }
       expose :commit, using: Entities::Commit, if: ->(_, _) { can_download_code? }
       expose :upcoming_release?, as: :upcoming_release
-      expose :milestones, using: Entities::Milestone, if: -> (release, _) { release.milestones.present? }
+      expose :milestones, using: Entities::Milestone, if: -> (release, _) { release.milestones.present? && can_read_milestone? }
       expose :commit_path, expose_nil: false
       expose :tag_path, expose_nil: false
       expose :evidence_sha, expose_nil: false, if: ->(_, _) { can_download_code? }
@@ -1389,6 +1389,10 @@ module API
       def can_download_code?
         Ability.allowed?(options[:current_user], :download_code, object.project)
       end
+
+      def can_read_milestone?
+        Ability.allowed?(options[:current_user], :read_milestone, object.project)
+      end
     end
 
     class Tag < Grape::Entity
diff --git a/lib/banzai/filter/relative_link_filter.rb b/lib/banzai/filter/relative_link_filter.rb
index 583b0081319..4f257189f8e 100644
--- a/lib/banzai/filter/relative_link_filter.rb
+++ b/lib/banzai/filter/relative_link_filter.rb
@@ -116,7 +116,7 @@ module Banzai
       end
 
       def process_link_to_upload_attr(html_attr)
-        path_parts = [Addressable::URI.unescape(html_attr.value)]
+        path_parts = [unescape_and_scrub_uri(html_attr.value)]
 
         if project
           path_parts.unshift(relative_url_root, project.full_path)
@@ -172,7 +172,7 @@ module Banzai
       end
 
       def cleaned_file_path(uri)
-        Addressable::URI.unescape(uri.path).scrub.delete("\0").chomp("/")
+        unescape_and_scrub_uri(uri.path).delete("\0").chomp("/")
       end
 
       def relative_file_path(uri)
@@ -184,7 +184,7 @@ module Banzai
       def request_path
         return unless context[:requested_path]
 
-        Addressable::URI.unescape(context[:requested_path]).chomp("/")
+        unescape_and_scrub_uri(context[:requested_path]).chomp("/")
       end
 
       # Convert a relative path into its correct location based on the currently
@@ -266,6 +266,12 @@ module Banzai
       def repository
         @repository ||= project&.repository
       end
+
+      private
+
+      def unescape_and_scrub_uri(uri)
+        Addressable::URI.unescape(uri).scrub
+      end
     end
   end
 end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index fa5560755a9..b573205a85f 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -8579,6 +8579,9 @@ msgstr ""
 msgid "GitHub import"
 msgstr ""
 
+msgid "GitLab / Unsubscribe"
+msgstr ""
+
 msgid "GitLab CI Linter has been moved"
 msgstr ""
 
diff --git a/scripts/sync-stable-branch.sh b/scripts/sync-stable-branch.sh
index b44bf26a151..1eb416bf4f5 100644
--- a/scripts/sync-stable-branch.sh
+++ b/scripts/sync-stable-branch.sh
@@ -35,6 +35,22 @@ then
     exit 1
 fi
 
+if [[ "$TARGET_PROJECT" != "gitlab-org/gitlab-foss" ]]
+then
+    echo 'This is a security FOSS merge train'
+    echo "Checking if $CI_COMMIT_SHA is available on canonical"
+
+    gitlab_com_commit_status=$(curl -s "https://gitlab.com/api/v4/projects/278964/repository/commits/$CI_COMMIT_SHA" | jq -M .status)
+
+    if [[ "$gitlab_com_commit_status" != "null" ]]
+    then
+       echo 'Commit available on canonical, skipping merge train'
+       exit 0
+    fi
+
+    echo 'Commit not available, triggering a merge train'
+fi
+
 curl -X POST \
     -F token="$MERGE_TRAIN_TRIGGER_TOKEN" \
     -F ref=master \
diff --git a/spec/controllers/profiles/notifications_controller_spec.rb b/spec/controllers/profiles/notifications_controller_spec.rb
index dbc408bcdd9..ede68744ac6 100644
--- a/spec/controllers/profiles/notifications_controller_spec.rb
+++ b/spec/controllers/profiles/notifications_controller_spec.rb
@@ -52,6 +52,35 @@ describe Profiles::NotificationsController do
         end.to exceed_query_limit(control)
       end
     end
+
+    context 'with project notifications' do
+      let!(:notification_setting) { create(:notification_setting, source: project, user: user, level: :watch) }
+
+      before do
+        sign_in(user)
+        get :show
+      end
+
+      context 'when project is public' do
+        let(:project) { create(:project, :public) }
+
+        it 'shows notification setting for project' do
+          expect(assigns(:project_notifications).map(&:source_id)).to include(project.id)
+        end
+      end
+
+      context 'when project is public' do
+        let(:project) { create(:project, :private) }
+
+        it 'shows notification setting for project' do
+          # notification settings for given project were created before project was set to private
+          expect(user.notification_settings.for_projects.map(&:source_id)).to include(project.id)
+
+          # check that notification settings for project where user does not have access are filtered
+          expect(assigns(:project_notifications)).to be_empty
+        end
+      end
+    end
   end
 
   describe 'POST update' do
diff --git a/spec/controllers/projects/releases_controller_spec.rb b/spec/controllers/projects/releases_controller_spec.rb
index e9fa3764117..750e9aabef0 100644
--- a/spec/controllers/projects/releases_controller_spec.rb
+++ b/spec/controllers/projects/releases_controller_spec.rb
@@ -167,7 +167,7 @@ describe Projects::ReleasesController do
   end
 
   describe 'GET #evidence' do
-    let(:tag_name) { "v1.1.0-evidence" }
+    let_it_be(:tag_name) { "v1.1.0-evidence" }
     let!(:release) { create(:release, :with_evidence, project: project, tag: tag_name) }
     let(:tag) { CGI.escape(release.tag) }
     let(:format) { :json }
@@ -220,6 +220,85 @@ describe Projects::ReleasesController do
         it_behaves_like 'successful request'
       end
     end
+
+    context 'when release is associated to a milestone which includes an issue' do
+      let_it_be(:project) { create(:project, :repository, :public) }
+      let_it_be(:issue) { create(:issue, project: project) }
+      let_it_be(:milestone) { create(:milestone, project: project, issues: [issue]) }
+      let_it_be(:release) { create(:release, project: project, tag: tag_name, milestones: [milestone]) }
+
+      before do
+        create(:evidence, release: release)
+      end
+
+      shared_examples_for 'does not show the issue in evidence' do
+        it do
+          subject
+
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(json_response['release']['milestones']
+            .all? { |milestone| milestone['issues'].nil? }).to eq(true)
+        end
+      end
+
+      shared_examples_for 'evidence not found' do
+        it do
+          subject
+
+          expect(response).to have_gitlab_http_status(:not_found)
+        end
+      end
+
+      shared_examples_for 'safely expose evidence' do
+        it_behaves_like 'does not show the issue in evidence'
+
+        context 'when the issue is confidential' do
+          let(:issue) { create(:issue, :confidential, project: project) }
+
+          it_behaves_like 'does not show the issue in evidence'
+        end
+
+        context 'when the user is the author of the confidential issue' do
+          let(:issue) { create(:issue, :confidential, project: project, author: user) }
+
+          it_behaves_like 'does not show the issue in evidence'
+        end
+
+        context 'when project is private' do
+          let!(:project) { create(:project, :repository, :private) }
+
+          it_behaves_like 'evidence not found'
+        end
+
+        context 'when project restricts the visibility of issues to project members only' do
+          let!(:project) { create(:project, :repository, :issues_private) }
+
+          it_behaves_like 'evidence not found'
+        end
+      end
+
+      context 'when user is non-project member' do
+        let(:user) { create(:user) }
+
+        it_behaves_like 'safely expose evidence'
+      end
+
+      context 'when user is auditor', if: Gitlab.ee? do
+        let(:user) { create(:user, :auditor) }
+
+        it_behaves_like 'safely expose evidence'
+      end
+
+      context 'when external authorization control is enabled' do
+        let(:user) { create(:user) }
+
+        before do
+          stub_application_setting(external_authorization_service_enabled: true)
+        end
+
+        it_behaves_like 'evidence not found'
+      end
+    end
   end
 
   private
diff --git a/spec/controllers/sent_notifications_controller_spec.rb b/spec/controllers/sent_notifications_controller_spec.rb
index 0e634d8ba99..4dd4f49dcf1 100644
--- a/spec/controllers/sent_notifications_controller_spec.rb
+++ b/spec/controllers/sent_notifications_controller_spec.rb
@@ -56,7 +56,7 @@ describe SentNotificationsController do
           get(:unsubscribe, params: { id: sent_notification.reply_key })
         end
 
-        shared_examples 'unsubscribing as anonymous' do
+        shared_examples 'unsubscribing as anonymous' do |project_visibility|
           it 'does not unsubscribe the user' do
             expect(noteable.subscribed?(user, target_project)).to be_truthy
           end
@@ -69,6 +69,18 @@ describe SentNotificationsController do
             expect(response.status).to eq(200)
             expect(response).to render_template :unsubscribe
           end
+
+          if project_visibility == :private
+            it 'does not show project name or path' do
+              expect(response.body).not_to include(noteable.project.name)
+              expect(response.body).not_to include(noteable.project.full_name)
+            end
+          else
+            it 'shows project name or path' do
+              expect(response.body).to include(noteable.project.name)
+              expect(response.body).to include(noteable.project.full_name)
+            end
+          end
         end
 
         context 'when project is public' do
@@ -79,7 +91,7 @@ describe SentNotificationsController do
               expect(response.body).to include(issue.title)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it_behaves_like 'unsubscribing as anonymous', :public
           end
 
           context 'when unsubscribing from confidential issue' do
@@ -90,7 +102,7 @@ describe SentNotificationsController do
               expect(response.body).to include(confidential_issue.to_reference)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it_behaves_like 'unsubscribing as anonymous', :public
           end
 
           context 'when unsubscribing from merge request' do
@@ -100,7 +112,12 @@ describe SentNotificationsController do
               expect(response.body).to include(merge_request.title)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it 'shows project name or path' do
+              expect(response.body).to include(issue.project.name)
+              expect(response.body).to include(issue.project.full_name)
+            end
+
+            it_behaves_like 'unsubscribing as anonymous', :public
           end
         end
 
@@ -110,11 +127,11 @@ describe SentNotificationsController do
           context 'when unsubscribing from issue' do
             let(:noteable) { issue }
 
-            it 'shows issue title' do
+            it 'does not show issue title' do
               expect(response.body).not_to include(issue.title)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it_behaves_like 'unsubscribing as anonymous', :private
           end
 
           context 'when unsubscribing from confidential issue' do
@@ -125,17 +142,17 @@ describe SentNotificationsController do
               expect(response.body).to include(confidential_issue.to_reference)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it_behaves_like 'unsubscribing as anonymous', :private
           end
 
           context 'when unsubscribing from merge request' do
             let(:noteable) { merge_request }
 
-            it 'shows merge request title' do
+            it 'dos not show merge request title' do
               expect(response.body).not_to include(merge_request.title)
             end
 
-            it_behaves_like 'unsubscribing as anonymous'
+            it_behaves_like 'unsubscribing as anonymous', :private
           end
         end
       end
diff --git a/spec/fixtures/api/schemas/evidences/milestone.json b/spec/fixtures/api/schemas/evidences/milestone.json
index ab27fdecde2..3ce0644225b 100644
--- a/spec/fixtures/api/schemas/evidences/milestone.json
+++ b/spec/fixtures/api/schemas/evidences/milestone.json
@@ -7,8 +7,7 @@
     "state",
     "iid",
     "created_at",
-    "due_date",
-    "issues"
+    "due_date"
   ],
   "properties": {
     "id": { "type": "integer" },
@@ -17,11 +16,7 @@
     "state": { "type": "string" },
     "iid": { "type": "integer" },
     "created_at": { "type": "date" },
-    "due_date": { "type": ["date", "null"] },
-    "issues": {
-      "type": "array",
-      "items": { "$ref": "issue.json" }
-    }
+    "due_date": { "type": ["date", "null"] }
   },
   "additionalProperties": false
 }
diff --git a/spec/fixtures/not_a_png.png b/spec/fixtures/not_a_png.png
new file mode 100644
index 00000000000..932f9efaed9
Binary files /dev/null and b/spec/fixtures/not_a_png.png differ
diff --git a/spec/lib/banzai/filter/relative_link_filter_spec.rb b/spec/lib/banzai/filter/relative_link_filter_spec.rb
index a17a645d4d0..9f467d7a6fd 100644
--- a/spec/lib/banzai/filter/relative_link_filter_spec.rb
+++ b/spec/lib/banzai/filter/relative_link_filter_spec.rb
@@ -128,6 +128,15 @@ describe Banzai::Filter::RelativeLinkFilter do
     expect { filter(act) }.not_to raise_error
   end
 
+  it 'does not raise an exception on URIs containing invalid utf-8 byte sequences in uploads' do
+    act = link("/uploads/%FF")
+    expect { filter(act) }.not_to raise_error
+  end
+
+  it 'does not raise an exception on URIs containing invalid utf-8 byte sequences in context requested path' do
+    expect { filter(link("files/test.md"), requested_path: '%FF') }.not_to raise_error
+  end
+
   it 'does not raise an exception with a garbled path' do
     act = link("open(/var/tmp/):%20/location%0Afrom:%20/test")
     expect { filter(act) }.not_to raise_error
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 314cc4e1d3c..b0f708bc0e7 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -2638,8 +2638,8 @@ describe User, :do_not_mock_admin_mode do
           add_user(:maintainer)
         end
 
-        it 'loads' do
-          expect(user.ci_owned_runners).to contain_exactly(runner)
+        it 'does not load' do
+          expect(user.ci_owned_runners).to be_empty
         end
       end
 
@@ -2654,6 +2654,20 @@ describe User, :do_not_mock_admin_mode do
       end
     end
 
+    shared_examples :group_member do
+      context 'when the user is owner' do
+        before do
+          add_user(:owner)
+        end
+
+        it 'loads' do
+          expect(user.ci_owned_runners).to contain_exactly(runner)
+        end
+      end
+
+      it_behaves_like :member
+    end
+
     context 'with groups projects runners' do
       let(:group) { create(:group) }
       let!(:project) { create(:project, group: group) }
@@ -2662,7 +2676,7 @@ describe User, :do_not_mock_admin_mode do
         group.add_user(user, access)
       end
 
-      it_behaves_like :member
+      it_behaves_like :group_member
     end
 
     context 'with groups runners' do
@@ -2673,14 +2687,14 @@ describe User, :do_not_mock_admin_mode do
         group.add_user(user, access)
       end
 
-      it_behaves_like :member
+      it_behaves_like :group_member
     end
 
     context 'with other projects runners' do
       let!(:project) { create(:project) }
 
       def add_user(access)
-        project.add_role(user, access)
+        project.add_user(user, access)
       end
 
       it_behaves_like :member
@@ -2698,7 +2712,7 @@ describe User, :do_not_mock_admin_mode do
         subgroup.add_user(another_user, :owner)
       end
 
-      it_behaves_like :member
+      it_behaves_like :group_member
     end
   end
 
diff --git a/spec/requests/api/graphql/gitlab_schema_spec.rb b/spec/requests/api/graphql/gitlab_schema_spec.rb
index 2aeb75a10b4..2cb8436662b 100644
--- a/spec/requests/api/graphql/gitlab_schema_spec.rb
+++ b/spec/requests/api/graphql/gitlab_schema_spec.rb
@@ -8,6 +8,18 @@ describe 'GitlabSchema configurations' do
   set(:project) { create(:project) }
 
   shared_examples 'imposing query limits' do
+    describe 'timeouts' do
+      context 'when timeout is reached' do
+        it 'shows an error' do
+          Timecop.scale(50000000) do # ludicrously large number because the timeout has to happen before the query even begins
+            subject
+
+            expect_graphql_errors_to_include /Timeout/
+          end
+        end
+      end
+    end
+
     describe '#max_complexity' do
       context 'when complexity is too high' do
         it 'shows an error' do
diff --git a/spec/requests/api/releases_spec.rb b/spec/requests/api/releases_spec.rb
index da04e852795..233f0497b7f 100644
--- a/spec/requests/api/releases_spec.rb
+++ b/spec/requests/api/releases_spec.rb
@@ -340,6 +340,40 @@ describe API::Releases do
 
           expect(response).to have_gitlab_http_status(:ok)
         end
+
+        context 'when release is associated to a milestone' do
+          let!(:release) do
+            create(:release, tag: 'v0.1', project: project, milestones: [milestone])
+          end
+
+          let(:milestone) { create(:milestone, project: project) }
+
+          it 'exposes milestones' do
+            get api("/projects/#{project.id}/releases/v0.1", non_project_member)
+
+            expect(json_response['milestones'].first['title']).to eq(milestone.title)
+          end
+
+          context 'when project restricts visibility of issues and merge requests' do
+            let!(:project) { create(:project, :repository, :public, :issues_private, :merge_requests_private) }
+
+            it 'does not expose milestones' do
+              get api("/projects/#{project.id}/releases/v0.1", non_project_member)
+
+              expect(json_response['milestones']).to be_nil
+            end
+          end
+
+          context 'when project restricts visibility of issues' do
+            let!(:project) { create(:project, :repository, :public, :issues_private) }
+
+            it 'exposes milestones' do
+              get api("/projects/#{project.id}/releases/v0.1", non_project_member)
+
+              expect(json_response['milestones'].first['title']).to eq(milestone.title)
+            end
+          end
+        end
       end
     end
   end
diff --git a/spec/requests/api/runners_spec.rb b/spec/requests/api/runners_spec.rb
index 8daba204d50..7bad30d107d 100644
--- a/spec/requests/api/runners_spec.rb
+++ b/spec/requests/api/runners_spec.rb
@@ -6,6 +6,7 @@ describe API::Runners do
   let(:admin) { create(:user, :admin) }
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
+  let(:group_maintainer) { create(:user) }
 
   let(:project) { create(:project, creator_id: user.id) }
   let(:project2) { create(:project, creator_id: user.id) }
@@ -20,6 +21,7 @@ describe API::Runners do
 
   before do
     # Set project access for users
+    create(:group_member, :maintainer, user: group_maintainer, group: group)
     create(:project_member, :maintainer, user: user, project: project)
     create(:project_member, :maintainer, user: user, project: project2)
     create(:project_member, :reporter, user: user2, project: project)
@@ -525,6 +527,20 @@ describe API::Runners do
           end.to change { Ci::Runner.project_type.count }.by(-1)
         end
 
+        it 'does not delete group runner with maintainer access' do
+          delete api("/runners/#{group_runner.id}", group_maintainer)
+
+          expect(response).to have_http_status(403)
+        end
+
+        it 'deletes group runner with owner access' do
+          expect do
+            delete api("/runners/#{group_runner.id}", user)
+
+            expect(response).to have_http_status(204)
+          end.to change { Ci::Runner.group_type.count }.by(-1)
+        end
+
         it_behaves_like '412 response' do
           let(:request) { api("/runners/#{project_runner.id}", user) }
         end
diff --git a/spec/support/shared_contexts/upload_type_check_shared_context.rb b/spec/support/shared_contexts/upload_type_check_shared_context.rb
new file mode 100644
index 00000000000..04c97500dd6
--- /dev/null
+++ b/spec/support/shared_contexts/upload_type_check_shared_context.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Construct an `uploader` variable that is configured to `check_upload_type`
+# with `mime_types` and `extensions`.
+shared_context 'uploader with type check' do
+  let(:uploader_class) do
+    Class.new(GitlabUploader) do
+      include UploadTypeCheck::Concern
+      storage :file
+    end
+  end
+
+  let(:mime_types) { nil }
+  let(:extensions) { nil }
+  let(:uploader) do
+    uploader_class.class_exec(mime_types, extensions) do |mime_types, extensions|
+      check_upload_type mime_types: mime_types, extensions: extensions
+    end
+    uploader_class.new(build_stubbed(:user))
+  end
+end
+
+shared_context 'stubbed MimeMagic mime type detection' do
+  let(:mime_type) { '' }
+  let(:magic_mime) { mime_type }
+  let(:ext_mime) { mime_type }
+  before do
+    magic_mime_obj = MimeMagic.new(magic_mime)
+    ext_mime_obj = MimeMagic.new(ext_mime)
+    allow(MimeMagic).to receive(:by_magic).with(anything).and_return(magic_mime_obj)
+    allow(MimeMagic).to receive(:by_path).with(anything).and_return(ext_mime_obj)
+  end
+end
diff --git a/spec/support/shared_examples/uploaders/upload_type_shared_examples.rb b/spec/support/shared_examples/uploaders/upload_type_shared_examples.rb
new file mode 100644
index 00000000000..91d2526cde2
--- /dev/null
+++ b/spec/support/shared_examples/uploaders/upload_type_shared_examples.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+def check_content_matches_extension!(file = double(read: nil, path: ''))
+  magic_file = UploadTypeCheck::MagicFile.new(file)
+  uploader.check_content_matches_extension!(magic_file)
+end
+
+shared_examples 'upload passes content type check' do
+  it 'does not raise error' do
+    expect { check_content_matches_extension! }.not_to raise_error
+  end
+end
+
+shared_examples 'upload fails content type check' do
+  it 'raises error' do
+    expect { check_content_matches_extension! }.to raise_error(CarrierWave::IntegrityError)
+  end
+end
+
+def upload_type_checked_filenames(filenames)
+  Array(filenames).each do |filename|
+    # Feed the uploader "some" content.
+    path = File.join('spec', 'fixtures', 'dk.png')
+    file = File.new(path, 'r')
+    # Rename the file with what we want.
+    allow(file).to receive(:path).and_return(filename)
+
+    # Force the content type to match the extension type.
+    mime_type = MimeMagic.by_path(filename)
+    allow(MimeMagic).to receive(:by_magic).and_return(mime_type)
+
+    uploaded_file = Rack::Test::UploadedFile.new(file, original_filename: filename)
+    uploader.cache!(uploaded_file)
+  end
+end
+
+def upload_type_checked_fixtures(upload_fixtures)
+  upload_fixtures = Array(upload_fixtures)
+  upload_fixtures.each do |upload_fixture|
+    path = File.join('spec', 'fixtures', upload_fixture)
+    uploader.cache!(fixture_file_upload(path))
+  end
+end
+
+shared_examples 'type checked uploads' do |upload_fixtures = nil, filenames: nil|
+  it 'check type' do
+    upload_fixtures = Array(upload_fixtures)
+    filenames = Array(filenames)
+
+    times = upload_fixtures.length + filenames.length
+    expect(uploader).to receive(:check_content_matches_extension!).exactly(times).times
+
+    upload_type_checked_fixtures(upload_fixtures) unless upload_fixtures.empty?
+    upload_type_checked_filenames(filenames) unless filenames.empty?
+  end
+end
+
+shared_examples 'skipped type checked uploads' do |upload_fixtures = nil, filenames: nil|
+  it 'skip type check' do
+    expect(uploader).not_to receive(:check_content_matches_extension!)
+
+    upload_type_checked_fixtures(upload_fixtures) if upload_fixtures
+    upload_type_checked_filenames(filenames) if filenames
+  end
+end
diff --git a/spec/uploaders/avatar_uploader_spec.rb b/spec/uploaders/avatar_uploader_spec.rb
index c0844360589..669f75b2ee8 100644
--- a/spec/uploaders/avatar_uploader_spec.rb
+++ b/spec/uploaders/avatar_uploader_spec.rb
@@ -46,4 +46,16 @@ describe AvatarUploader do
       expect(uploader.absolute_path).to eq(absolute_path)
     end
   end
+
+  context 'upload type check' do
+    AvatarUploader::SAFE_IMAGE_EXT.each do |ext|
+      context "#{ext} extension" do
+        it_behaves_like 'type checked uploads', filenames: "image.#{ext}"
+      end
+    end
+
+    context 'skip image/svg+xml integrity check' do
+      it_behaves_like 'skipped type checked uploads', filenames: 'image.svg'
+    end
+  end
 end
diff --git a/spec/uploaders/favicon_uploader_spec.rb b/spec/uploaders/favicon_uploader_spec.rb
new file mode 100644
index 00000000000..4d6c849883a
--- /dev/null
+++ b/spec/uploaders/favicon_uploader_spec.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe FaviconUploader do
+  let_it_be(:model) { build_stubbed(:user) }
+  let_it_be(:uploader) { described_class.new(model, :favicon) }
+
+  context 'upload type check' do
+    FaviconUploader::EXTENSION_WHITELIST.each do |ext|
+      context "#{ext} extension" do
+        it_behaves_like 'type checked uploads', filenames: "image.#{ext}"
+      end
+    end
+  end
+
+  context 'upload non-whitelisted file extensions' do
+    it 'will deny upload' do
+      path = File.join('spec', 'fixtures', 'banana_sample.gif')
+      fixture_file = fixture_file_upload(path)
+      expect { uploader.cache!(fixture_file) }.to raise_exception(CarrierWave::IntegrityError)
+    end
+  end
+end
diff --git a/spec/uploaders/upload_type_check_spec.rb b/spec/uploaders/upload_type_check_spec.rb
new file mode 100644
index 00000000000..a4895f6a956
--- /dev/null
+++ b/spec/uploaders/upload_type_check_spec.rb
@@ -0,0 +1,124 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe UploadTypeCheck do
+  include_context 'uploader with type check'
+
+  def upload_fixture(filename)
+    fixture_file_upload(File.join('spec', 'fixtures', filename))
+  end
+
+  describe '#check_content_matches_extension! callback using file upload' do
+    context 'when extension matches contents' do
+      it 'not raise error on upload' do
+        expect { uploader.cache!(upload_fixture('banana_sample.gif')) }.not_to raise_error
+      end
+    end
+
+    context 'when extension does not match contents' do
+      it 'raise error' do
+        expect { uploader.cache!(upload_fixture('not_a_png.png')) }.to raise_error(CarrierWave::IntegrityError)
+      end
+    end
+  end
+
+  describe '#check_content_matches_extension! callback using stubs' do
+    include_context 'stubbed MimeMagic mime type detection'
+
+    context 'when no extension and with ambiguous/text content' do
+      let(:magic_mime) { '' }
+      let(:ext_mime) { '' }
+
+      it_behaves_like 'upload passes content type check'
+    end
+
+    context 'when no extension and with non-text content' do
+      let(:magic_mime) { 'image/gif' }
+      let(:ext_mime) { '' }
+
+      it_behaves_like 'upload fails content type check'
+    end
+
+    # Most text files will exhibit this behaviour.
+    context 'when ambiguous content with text extension' do
+      let(:magic_mime) { '' }
+      let(:ext_mime) { 'text/plain' }
+
+      it_behaves_like 'upload passes content type check'
+    end
+
+    context 'when text content with text extension' do
+      let(:magic_mime) { 'text/plain' }
+      let(:ext_mime) { 'text/plain' }
+
+      it_behaves_like 'upload passes content type check'
+    end
+
+    context 'when ambiguous content with non-text extension' do
+      let(:magic_mime) { '' }
+      let(:ext_mime) { 'application/zip' }
+
+      it_behaves_like 'upload fails content type check'
+    end
+
+    # These are the types when uploading a .dmg
+    context 'when content and extension do not match' do
+      let(:magic_mime) { 'application/x-bzip' }
+      let(:ext_mime) { 'application/x-apple-diskimage' }
+
+      it_behaves_like 'upload fails content type check'
+    end
+  end
+
+  describe '#check_content_matches_extension! mime_type filtering' do
+    context 'without mime types' do
+      let(:mime_types) { nil }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt rails_sample.jpg]
+    end
+
+    context 'with mime types string' do
+      let(:mime_types) { 'text/plain' }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt]
+      it_behaves_like 'skipped type checked uploads', %w[dk.png]
+    end
+
+    context 'with mime types regex' do
+      let(:mime_types) { [/image\/(gif|png)/] }
+
+      it_behaves_like 'type checked uploads', %w[banana_sample.gif dk.png]
+      it_behaves_like 'skipped type checked uploads', %w[doc_sample.txt]
+    end
+
+    context 'with mime types array' do
+      let(:mime_types) { ['text/plain', /image\/png/] }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt dk.png]
+      it_behaves_like 'skipped type checked uploads', %w[audio_sample.wav]
+    end
+  end
+
+  describe '#check_content_matches_extension! extensions filtering' do
+    context 'without extensions' do
+      let(:extensions) { nil }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt dk.png]
+    end
+
+    context 'with extensions string' do
+      let(:extensions) { 'txt' }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt]
+      it_behaves_like 'skipped type checked uploads', %w[rails_sample.jpg]
+    end
+
+    context 'with extensions array of strings' do
+      let(:extensions) { %w[txt png] }
+
+      it_behaves_like 'type checked uploads', %w[doc_sample.txt dk.png]
+      it_behaves_like 'skipped type checked uploads', %w[audio_sample.wav]
+    end
+  end
+end