CVE-2026-49215CWE-352

Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted

Low · published July 17, 2026

CVSS v4.0
2.1
EPSS
0%
Percentile
6.9
In the wild
Unconfirmed
What it is

Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\EventListener\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.

The record
Technical detail
CVSS v4.0
2.1 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS
0.00177 · 6.9th percentile
Weakness
CWE-352 · Cross-Site Request Forgery (CSRF)
Published
2026-07-17T16:16Z
EPSS history
Timeline
  • 17 JUL 16:16Z
    Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted
    cvelistv5