Description
Symfony\UX\LiveComponent\Controller\BatchActionController::__invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry (event subscribers, validators, Doctrine, rendering). The array size is never bounded, so an authenticated client can submit a single _batch request containing thousands of actions and exhaust CPU, memory, and database connections on the application server.
Resolution
BatchActionController now enforces an upper bound of 50 actions per _batch request (MAX_ACTIONS_PER_BATCH) and rejects larger payloads up front with a BadRequestHttpException. The matching JavaScript backend was also updated to split larger client-side batches into multiple requests so legitimate usage isn't affected.
The patch for this issue is available here for branch 2.x (and forward-ported to 3.x).
Credits
We would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.
Description
Symfony\UX\LiveComponent\Controller\BatchActionController::__invoke()iterates over the client-suppliedactionsarray and issues a fullHttpKernelsub-request for each entry (event subscribers, validators, Doctrine, rendering). The array size is never bounded, so an authenticated client can submit a single_batchrequest containing thousands of actions and exhaust CPU, memory, and database connections on the application server.Resolution
BatchActionControllernow enforces an upper bound of 50 actions per_batchrequest (MAX_ACTIONS_PER_BATCH) and rejects larger payloads up front with aBadRequestHttpException. The matching JavaScript backend was also updated to split larger client-side batches into multiple requests so legitimate usage isn't affected.The patch for this issue is available here for branch 2.x (and forward-ported to 3.x).
Credits
We would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.