CVE-2026-49209: Symfony Ux

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Symfony UX is a JavaScript ecosystem for Symfony. From 2.5.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Controller\BatchActionController::__invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry; because the array size is never bounded, an authenticated client can submit a single _batch request containing thousands of actions and exhaust CPU, memory, and database connections on the application server. This issue is fixed in versions 2.36.0 and 3.1.0.

Affected products

• Symfony Ux: from 2.5.0, before 2.36.0 (fixed in 2.36.0); version 3.0.0 only

Published 2026-07-17. Last modified 2026-07-20.