diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 36f37221c584f68fd5f96b1679777e24ed09cf2e..c993048077060c57750f84ffbdbc0cb8a40993ec 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -134,7 +134,7 @@ class ProjectsController < ApplicationController
   def autocomplete_sources
     note_type = params['type']
     note_id = params['type_id']
-    autocomplete = ::Projects::AutocompleteService.new(@project)
+    autocomplete = ::Projects::AutocompleteService.new(@project, current_user)
     participants = ::Projects::ParticipantsService.new(@project, current_user).execute(note_type, note_id)
 
     @suggestions = {
diff --git a/app/services/projects/autocomplete_service.rb b/app/services/projects/autocomplete_service.rb
index 7408e09ed1e9df60df177b33cade2521db187cda..ba50305dbd5fca2831c1534cd4a8a0eec4f94a57 100644
--- a/app/services/projects/autocomplete_service.rb
+++ b/app/services/projects/autocomplete_service.rb
@@ -1,11 +1,7 @@
 module Projects
   class AutocompleteService < BaseService
-    def initialize(project)
-      @project = project
-    end
-
     def issues
-      @project.issues.opened.select([:iid, :title])
+      @project.issues.visible_to_user(current_user).opened.select([:iid, :title])
     end
 
     def merge_requests
diff --git a/spec/services/projects/autocomplete_service_spec.rb b/spec/services/projects/autocomplete_service_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..6108c26a78b862808dacd7b9b1d80e6757df8f5f
--- /dev/null
+++ b/spec/services/projects/autocomplete_service_spec.rb
@@ -0,0 +1,79 @@
+require 'spec_helper'
+
+describe Projects::AutocompleteService, services: true do
+  describe '#issues' do
+    describe 'confidential issues' do
+      let(:author) { create(:user) }
+      let(:assignee) { create(:user) }
+      let(:non_member) { create(:user) }
+      let(:member) { create(:user) }
+      let(:admin) { create(:admin) }
+      let(:project) { create(:empty_project, :public) }
+      let!(:issue) { create(:issue, project: project, title: 'Issue 1') }
+      let!(:security_issue_1) { create(:issue, :confidential, project: project, title: 'Security issue 1', author: author) }
+      let!(:security_issue_2) { create(:issue, :confidential, title: 'Security issue 2', project: project, assignee: assignee) }
+
+      it 'should not list project confidential issues for guests' do
+        autocomplete = described_class.new(project, nil)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).not_to include security_issue_1.iid
+        expect(issues).not_to include security_issue_2.iid
+        expect(issues.count).to eq 1
+      end
+
+      it 'should not list project confidential issues for non project members' do
+        autocomplete = described_class.new(project, non_member)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).not_to include security_issue_1.iid
+        expect(issues).not_to include security_issue_2.iid
+        expect(issues.count).to eq 1
+      end
+
+      it 'should list project confidential issues for author' do
+        autocomplete = described_class.new(project, author)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).to include security_issue_1.iid
+        expect(issues).not_to include security_issue_2.iid
+        expect(issues.count).to eq 2
+      end
+
+      it 'should list project confidential issues for assignee' do
+        autocomplete = described_class.new(project, assignee)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).not_to include security_issue_1.iid
+        expect(issues).to include security_issue_2.iid
+        expect(issues.count).to eq 2
+      end
+
+      it 'should list project confidential issues for project members' do
+        project.team << [member, :developer]
+
+        autocomplete = described_class.new(project, member)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).to include security_issue_1.iid
+        expect(issues).to include security_issue_2.iid
+        expect(issues.count).to eq 3
+      end
+
+      it 'should list all project issues for admin' do
+        autocomplete = described_class.new(project, admin)
+        issues = autocomplete.issues.map(&:iid)
+
+        expect(issues).to include issue.iid
+        expect(issues).to include security_issue_1.iid
+        expect(issues).to include security_issue_2.iid
+        expect(issues.count).to eq 3
+      end
+    end
+  end
+end