app/Actions/Projects/BuildProjectBacklogPayload.php

@@ -59,9 +59,24 @@ class BuildProjectBacklogPayload
             )->resolve(),
             'users' => UserResource::collection(
                 User::query()
+                    ->whereIn('id', $this->visibleUserIds($project))
                     ->orderBy('name')
                     ->get(),
             )->resolve(),
         ];
     }
+
+    /**
+     * @return array<int, int>
+     */
+    private function visibleUserIds(Project $project): array
+    {
+        return User::query()
+            ->get()
+            ->filter(fn (User $candidate): bool => $this->permissionService->allows($candidate, Permission::ProjectRead, $project))
+            ->pluck('id')
+            ->map(fn (mixed $userId): int => (int) $userId)
+            ->values()
+            ->all();
+    }
 }

app/Actions/Projects/BuildProjectTicketDetailPayload.php

@@ -116,9 +116,24 @@ class BuildProjectTicketDetailPayload
             'ticketTypes' => TicketTypeResource::collection($project->ticketTypes()->get())->resolve(),
             'users' => UserResource::collection(
                 User::query()
+                    ->whereIn('id', $this->visibleUserIds($project))
                     ->orderBy('name')
                     ->get(),
             )->resolve(),
         ];
     }
+
+    /**
+     * @return array<int, int>
+     */
+    private function visibleUserIds(Project $project): array
+    {
+        return User::query()
+            ->get()
+            ->filter(fn (User $candidate): bool => $this->permissionService->allows($candidate, Permission::ProjectRead, $project))
+            ->pluck('id')
+            ->map(fn (mixed $userId): int => (int) $userId)
+            ->values()
+            ->all();
+    }
 }

tests/Feature/Api/SettingsApiTest.php

@@ -4,6 +4,7 @@ namespace Tests\Feature\Api;
 
 use App\Actions\ProjectTicketMetadata\InitializeProjectTicketMetadata;
 use App\Models\Project;
+use App\Models\Team;
 use App\Models\User;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Support\Facades\Http;
@@ -149,6 +150,43 @@ class SettingsApiTest extends TestCase
             ->assertNoContent();
     }
 
+    public function test_project_payloads_only_return_users_who_can_view_the_project(): void
+    {
+        [$user, $project] = $this->projectContext();
+        $viewer = User::factory()->create(['name' => 'Visible User']);
+        User::factory()->create(['name' => 'Hidden User']);
+        $teamViewer = User::factory()->create(['name' => 'Team Viewer']);
+        $team = Team::factory()->create();
+
+        $this->syncProjectPermissions($project, $viewer, ['view']);
+        $team->users()->attach($teamViewer);
+        $this->syncProjectPermissions($project, $team, ['view']);
+
+        $ticket = $project->tickets()->firstOrCreate([
+            'sequence_number' => 1,
+        ], [
+            'ticket_key' => 'CORE-1',
+            'ticket_priority_id' => $project->ticketPriorities()->firstOrFail()->id,
+            'ticket_status_id' => $project->ticketStatuses()->firstOrFail()->id,
+            'ticket_type_id' => $project->ticketTypes()->where('is_parent', false)->firstOrFail()->id,
+            'title' => 'Scoped users ticket',
+        ]);
+
+        $this->actingAs($user)
+            ->getJson(route('api.projects.backlog', $project))
+            ->assertOk()
+            ->assertJsonPath('data.users.0.name', 'Team Viewer')
+            ->assertJsonPath('data.users.1.name', 'Visible User')
+            ->assertJsonCount(2, 'data.users');
+
+        $this->actingAs($user)
+            ->getJson(route('api.projects.tickets.show', [$project, $ticket]))
+            ->assertOk()
+            ->assertJsonPath('data.users.0.name', 'Team Viewer')
+            ->assertJsonPath('data.users.1.name', 'Visible User')
+            ->assertJsonCount(2, 'data.users');
+    }
+
     public function test_project_repositories_and_user_git_connections_are_available(): void
     {
         Http::preventStrayRequests();