diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index 1088e6a253..961228f949 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -237,7 +237,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
 
         $this->deployment_uuid = $this->application_deployment_queue->deployment_uuid;
         $this->pull_request_id = $this->application_deployment_queue->pull_request_id;
-        $this->commit = $this->application_deployment_queue->commit;
+        $this->commit = validateGitRef($this->application_deployment_queue->commit, 'deployment commit');
         $this->rollback = $this->application_deployment_queue->rollback;
         $this->disableBuildCache = $this->application->settings->disable_build_cache;
         $this->force_rebuild = $this->application_deployment_queue->force_rebuild;
diff --git a/bootstrap/helpers/applications.php b/bootstrap/helpers/applications.php
index 2fb0bb3f53..7743304c34 100644
--- a/bootstrap/helpers/applications.php
+++ b/bootstrap/helpers/applications.php
@@ -14,6 +14,7 @@ use Spatie\Url\Url;
 function queue_application_deployment(Application $application, string $deployment_uuid, ?int $pull_request_id = 0, ?string $commit = null, bool $force_rebuild = false, bool $is_webhook = false, bool $is_api = false, bool $restart_only = false, ?string $git_type = null, bool $no_questions_asked = false, ?Server $server = null, ?StandaloneDocker $destination = null, bool $only_this_server = false, bool $rollback = false, ?string $docker_registry_image_tag = null)
 {
     $commit = $commit ?: ($application->git_commit_sha ?: 'HEAD');
+    $commit = validateGitRef($commit, 'deployment commit');
     $application_id = $application->id;
     $deployment_link = Url::fromString($application->link()."/deployment/{$deployment_uuid}");
     $deployment_url = $deployment_link->getPath();
diff --git a/tests/Feature/QueueApplicationDeploymentCommitTest.php b/tests/Feature/QueueApplicationDeploymentCommitTest.php
index 8273a5c61c..f5a8bb110e 100644
--- a/tests/Feature/QueueApplicationDeploymentCommitTest.php
+++ b/tests/Feature/QueueApplicationDeploymentCommitTest.php
@@ -45,6 +45,53 @@ function makeApplication(int $environmentId, int $destinationId, ?string $gitCom
 }
 
 describe('queue_application_deployment commit resolution', function () {
+    test('rejects a commit with disallowed characters before creating a deployment', function () {
+        $application = makeApplication($this->environment->id, $this->destination->id, 'HEAD');
+
+        expect(fn () => queue_application_deployment(
+            application: $application,
+            deployment_uuid: 'invalid-queued-commit',
+            commit: 'abc;not-a-ref',
+            is_webhook: true,
+        ))->toThrow(Exception::class, 'Invalid deployment commit');
+
+        $this->assertDatabaseMissing('application_deployment_queue', [
+            'deployment_uuid' => 'invalid-queued-commit',
+        ]);
+        Bus::assertNotDispatched(ApplicationDeploymentJob::class);
+    });
+
+    test('validates the application fallback commit before creating a deployment', function () {
+        $application = makeApplication(
+            $this->environment->id,
+            $this->destination->id,
+            '$(not-a-ref)',
+        );
+
+        expect(fn () => queue_application_deployment(
+            application: $application,
+            deployment_uuid: 'invalid-fallback-commit',
+        ))->toThrow(Exception::class, 'Invalid deployment commit');
+
+        $this->assertDatabaseMissing('application_deployment_queue', [
+            'deployment_uuid' => 'invalid-fallback-commit',
+        ]);
+        Bus::assertNotDispatched(ApplicationDeploymentJob::class);
+    });
+
+    test('rejects a stored queue commit with disallowed characters', function () {
+        $application = makeApplication($this->environment->id, $this->destination->id, 'HEAD');
+        queue_application_deployment($application, 'stored-invalid-commit');
+
+        $deployment = ApplicationDeploymentQueue::query()
+            ->where('deployment_uuid', 'stored-invalid-commit')
+            ->sole();
+        $deployment->update(['commit' => "abc\nnot-a-ref"]);
+
+        expect(fn () => new ApplicationDeploymentJob($deployment->id))
+            ->toThrow(Exception::class, 'Invalid deployment commit');
+    });
+
     test('records a team audit event when a user queues a deployment', function () {
         $user = User::factory()->create();
         $this->team->members()->attach($user, ['role' => 'owner']);