diff --git a/CHANGELOG b/CHANGELOG
index bafdc8dbc8e..48e38899607 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -21,6 +21,7 @@ v 8.8.0 (unreleased)
   - Bump mail_room to 0.7.0 to fix stuck IDLE connections
   - Remove future dates from contribution calendar graph.
   - Support e-mail notifications for comments on project snippets
+  - Fix API leak of notes of unauthorized issues, snippets and merge requests
   - Use ActionDispatch Remote IP for Akismet checking
   - Fix error when visiting commit builds page before build was updated
   - Add 'l' shortcut to open Label dropdown on issuables and 'i' to create new issue on a project
diff --git a/lib/api/notes.rb b/lib/api/notes.rb
index 71a53e6f0d6..d4fcfd3d4d3 100644
--- a/lib/api/notes.rb
+++ b/lib/api/notes.rb
@@ -19,20 +19,24 @@ module API
         #   GET /projects/:id/issues/:noteable_id/notes
         #   GET /projects/:id/snippets/:noteable_id/notes
         get ":id/#{noteables_str}/:#{noteable_id_str}/notes" do
-          @noteable = user_project.send(:"#{noteables_str}").find(params[:"#{noteable_id_str}"])
+          @noteable = user_project.send(noteables_str.to_sym).find(params[noteable_id_str.to_sym])
 
-          # We exclude notes that are cross-references and that cannot be viewed
-          # by the current user. By doing this exclusion at this level and not
-          # at the DB query level (which we cannot in that case), the current
-          # page can have less elements than :per_page even if
-          # there's more than one page.
-          notes =
-            # paginate() only works with a relation. This could lead to a
-            # mismatch between the pagination headers info and the actual notes
-            # array returned, but this is really a edge-case.
-            paginate(@noteable.notes).
-            reject { |n| n.cross_reference_not_visible_for?(current_user) }
-          present notes, with: Entities::Note
+          if can?(current_user, noteable_read_ability_name(@noteable), @noteable)
+            # We exclude notes that are cross-references and that cannot be viewed
+            # by the current user. By doing this exclusion at this level and not
+            # at the DB query level (which we cannot in that case), the current
+            # page can have less elements than :per_page even if
+            # there's more than one page.
+            notes =
+              # paginate() only works with a relation. This could lead to a
+              # mismatch between the pagination headers info and the actual notes
+              # array returned, but this is really a edge-case.
+              paginate(@noteable.notes).
+              reject { |n| n.cross_reference_not_visible_for?(current_user) }
+            present notes, with: Entities::Note
+          else
+            not_found!("Notes")
+          end
         end
 
         # Get a single +noteable+ note
@@ -45,13 +49,14 @@ module API
         #   GET /projects/:id/issues/:noteable_id/notes/:note_id
         #   GET /projects/:id/snippets/:noteable_id/notes/:note_id
         get ":id/#{noteables_str}/:#{noteable_id_str}/notes/:note_id" do
-          @noteable = user_project.send(:"#{noteables_str}").find(params[:"#{noteable_id_str}"])
+          @noteable = user_project.send(noteables_str.to_sym).find(params[noteable_id_str.to_sym])
           @note = @noteable.notes.find(params[:note_id])
+          can_read_note = can?(current_user, noteable_read_ability_name(@noteable), @noteable) && !@note.cross_reference_not_visible_for?(current_user)
 
-          if @note.cross_reference_not_visible_for?(current_user)
-            not_found!("Note")
-          else
+          if can_read_note
             present @note, with: Entities::Note
+          else
+            not_found!("Note")
           end
         end
 
@@ -136,5 +141,11 @@ module API
         end
       end
     end
+
+    helpers do
+      def noteable_read_ability_name(noteable)
+        "read_#{noteable.class.to_s.underscore.downcase}".to_sym
+      end
+    end
   end
 end
diff --git a/spec/requests/api/notes_spec.rb b/spec/requests/api/notes_spec.rb
index 49091fc0f49..ed1ed5aeb95 100644
--- a/spec/requests/api/notes_spec.rb
+++ b/spec/requests/api/notes_spec.rb
@@ -3,7 +3,7 @@ require 'spec_helper'
 describe API::API, api: true  do
   include ApiHelpers
   let(:user) { create(:user) }
-  let!(:project) { create(:project, namespace: user.namespace) }
+  let!(:project) { create(:project, :public, namespace: user.namespace) }
   let!(:issue) { create(:issue, project: project, author: user) }
   let!(:merge_request) { create(:merge_request, source_project: project, target_project: project, author: user) }
   let!(:snippet) { create(:project_snippet, project: project, author: user) }
@@ -39,6 +39,7 @@ describe API::API, api: true  do
     context "when noteable is an Issue" do
       it "should return an array of issue notes" do
         get api("/projects/#{project.id}/issues/#{issue.id}/notes", user)
+
         expect(response.status).to eq(200)
         expect(json_response).to be_an Array
         expect(json_response.first['body']).to eq(issue_note.note)
@@ -46,20 +47,33 @@ describe API::API, api: true  do
 
       it "should return a 404 error when issue id not found" do
         get api("/projects/#{project.id}/issues/12345/notes", user)
+
         expect(response.status).to eq(404)
       end
 
-      context "that references a private issue" do
+      context "and current user cannot view the notes" do
         it "should return an empty array" do
           get api("/projects/#{ext_proj.id}/issues/#{ext_issue.id}/notes", user)
+
           expect(response.status).to eq(200)
           expect(json_response).to be_an Array
           expect(json_response).to be_empty
         end
 
+        context "and issue is confidential" do
+          before { ext_issue.update_attributes(confidential: true) }
+
+          it "returns 404" do
+            get api("/projects/#{ext_proj.id}/issues/#{ext_issue.id}/notes", user)
+
+            expect(response.status).to eq(404)
+          end
+        end
+
         context "and current user can view the note" do
           it "should return an empty array" do
             get api("/projects/#{ext_proj.id}/issues/#{ext_issue.id}/notes", private_user)
+
             expect(response.status).to eq(200)
             expect(json_response).to be_an Array
             expect(json_response.first['body']).to eq(cross_reference_note.note)
@@ -71,6 +85,7 @@ describe API::API, api: true  do
     context "when noteable is a Snippet" do
       it "should return an array of snippet notes" do
         get api("/projects/#{project.id}/snippets/#{snippet.id}/notes", user)
+
         expect(response.status).to eq(200)
         expect(json_response).to be_an Array
         expect(json_response.first['body']).to eq(snippet_note.note)
@@ -78,6 +93,13 @@ describe API::API, api: true  do
 
       it "should return a 404 error when snippet id not found" do
         get api("/projects/#{project.id}/snippets/42/notes", user)
+
+        expect(response.status).to eq(404)
+      end
+
+      it "returns 404 when not authorized" do
+        get api("/projects/#{project.id}/snippets/#{snippet.id}/notes", private_user)
+
         expect(response.status).to eq(404)
       end
     end
@@ -85,6 +107,7 @@ describe API::API, api: true  do
     context "when noteable is a Merge Request" do
       it "should return an array of merge_requests notes" do
         get api("/projects/#{project.id}/merge_requests/#{merge_request.id}/notes", user)
+
         expect(response.status).to eq(200)
         expect(json_response).to be_an Array
         expect(json_response.first['body']).to eq(merge_request_note.note)
@@ -92,6 +115,13 @@ describe API::API, api: true  do
 
       it "should return a 404 error if merge request id not found" do
         get api("/projects/#{project.id}/merge_requests/4444/notes", user)
+
+        expect(response.status).to eq(404)
+      end
+
+      it "returns 404 when not authorized" do
+        get api("/projects/#{project.id}/merge_requests/4444/notes", private_user)
+
         expect(response.status).to eq(404)
       end
     end
@@ -101,24 +131,39 @@ describe API::API, api: true  do
     context "when noteable is an Issue" do
       it "should return an issue note by id" do
         get api("/projects/#{project.id}/issues/#{issue.id}/notes/#{issue_note.id}", user)
+
         expect(response.status).to eq(200)
         expect(json_response['body']).to eq(issue_note.note)
       end
 
       it "should return a 404 error if issue note not found" do
         get api("/projects/#{project.id}/issues/#{issue.id}/notes/12345", user)
+
         expect(response.status).to eq(404)
       end
 
-      context "that references a private issue" do
+      context "and current user cannot view the note" do
         it "should return a 404 error" do
           get api("/projects/#{ext_proj.id}/issues/#{ext_issue.id}/notes/#{cross_reference_note.id}", user)
+
           expect(response.status).to eq(404)
         end
 
+        context "when issue is confidential" do
+          before { issue.update_attributes(confidential: true) }
+
+          it "returns 404" do
+            get api("/projects/#{project.id}/issues/#{issue.id}/notes/#{issue_note.id}", private_user)
+
+            expect(response.status).to eq(404)
+          end
+        end
+
+
         context "and current user can view the note" do
           it "should return an issue note by id" do
             get api("/projects/#{ext_proj.id}/issues/#{ext_issue.id}/notes/#{cross_reference_note.id}", private_user)
+
             expect(response.status).to eq(200)
             expect(json_response['body']).to eq(cross_reference_note.note)
           end
@@ -129,12 +174,14 @@ describe API::API, api: true  do
     context "when noteable is a Snippet" do
       it "should return a snippet note by id" do
         get api("/projects/#{project.id}/snippets/#{snippet.id}/notes/#{snippet_note.id}", user)
+
         expect(response.status).to eq(200)
         expect(json_response['body']).to eq(snippet_note.note)
       end
 
       it "should return a 404 error if snippet note not found" do
         get api("/projects/#{project.id}/snippets/#{snippet.id}/notes/12345", user)
+
         expect(response.status).to eq(404)
       end
     end
@@ -144,6 +191,7 @@ describe API::API, api: true  do
     context "when noteable is an Issue" do
       it "should create a new issue note" do
         post api("/projects/#{project.id}/issues/#{issue.id}/notes", user), body: 'hi!'
+
         expect(response.status).to eq(201)
         expect(json_response['body']).to eq('hi!')
         expect(json_response['author']['username']).to eq(user.username)
@@ -151,11 +199,13 @@ describe API::API, api: true  do
 
       it "should return a 400 bad request error if body not given" do
         post api("/projects/#{project.id}/issues/#{issue.id}/notes", user)
+
         expect(response.status).to eq(400)
       end
 
       it "should return a 401 unauthorized error if user not authenticated" do
         post api("/projects/#{project.id}/issues/#{issue.id}/notes"), body: 'hi!'
+
         expect(response.status).to eq(401)
       end
 
@@ -164,6 +214,7 @@ describe API::API, api: true  do
           creation_time = 2.weeks.ago
           post api("/projects/#{project.id}/issues/#{issue.id}/notes", user),
             body: 'hi!', created_at: creation_time
+
           expect(response.status).to eq(201)
           expect(json_response['body']).to eq('hi!')
           expect(json_response['author']['username']).to eq(user.username)
@@ -176,6 +227,7 @@ describe API::API, api: true  do
     context "when noteable is a Snippet" do
       it "should create a new snippet note" do
         post api("/projects/#{project.id}/snippets/#{snippet.id}/notes", user), body: 'hi!'
+
         expect(response.status).to eq(201)
         expect(json_response['body']).to eq('hi!')
         expect(json_response['author']['username']).to eq(user.username)
@@ -183,11 +235,13 @@ describe API::API, api: true  do
 
       it "should return a 400 bad request error if body not given" do
         post api("/projects/#{project.id}/snippets/#{snippet.id}/notes", user)
+
         expect(response.status).to eq(400)
       end
 
       it "should return a 401 unauthorized error if user not authenticated" do
         post api("/projects/#{project.id}/snippets/#{snippet.id}/notes"), body: 'hi!'
+
         expect(response.status).to eq(401)
       end
     end
@@ -227,6 +281,7 @@ describe API::API, api: true  do
       it 'should return modified note' do
         put api("/projects/#{project.id}/issues/#{issue.id}/"\
                   "notes/#{issue_note.id}", user), body: 'Hello!'
+
         expect(response.status).to eq(200)
         expect(json_response['body']).to eq('Hello!')
       end
@@ -234,12 +289,14 @@ describe API::API, api: true  do
       it 'should return a 404 error when note id not found' do
         put api("/projects/#{project.id}/issues/#{issue.id}/notes/12345", user),
                 body: 'Hello!'
+
         expect(response.status).to eq(404)
       end
 
       it 'should return a 400 bad request error if body not given' do
         put api("/projects/#{project.id}/issues/#{issue.id}/"\
                   "notes/#{issue_note.id}", user)
+
         expect(response.status).to eq(400)
       end
     end
@@ -248,6 +305,7 @@ describe API::API, api: true  do
       it 'should return modified note' do
         put api("/projects/#{project.id}/snippets/#{snippet.id}/"\
                   "notes/#{snippet_note.id}", user), body: 'Hello!'
+
         expect(response.status).to eq(200)
         expect(json_response['body']).to eq('Hello!')
       end
@@ -255,6 +313,7 @@ describe API::API, api: true  do
       it 'should return a 404 error when note id not found' do
         put api("/projects/#{project.id}/snippets/#{snippet.id}/"\
                   "notes/12345", user), body: "Hello!"
+
         expect(response.status).to eq(404)
       end
     end
@@ -263,6 +322,7 @@ describe API::API, api: true  do
       it 'should return modified note' do
         put api("/projects/#{project.id}/merge_requests/#{merge_request.id}/"\
                   "notes/#{merge_request_note.id}", user), body: 'Hello!'
+
         expect(response.status).to eq(200)
         expect(json_response['body']).to eq('Hello!')
       end
@@ -270,6 +330,7 @@ describe API::API, api: true  do
       it 'should return a 404 error when note id not found' do
         put api("/projects/#{project.id}/merge_requests/#{merge_request.id}/"\
                   "notes/12345", user), body: "Hello!"
+
         expect(response.status).to eq(404)
       end
     end