Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M

CVE-2026-49215Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted

Low 2.1

In plain English

A low-severity cross-site request forgery in ux from symfony. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)2.1Low

Exploit odds (30 days)0.2%top 92.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	symfony/ux-live-component	2.36.0	GHSA-4m4j-hmqq-3gxm
Packagist	symfony/ux-live-component	3.1.0	GHSA-4m4j-hmqq-3gxm

Affected products (as reported)

Vendor	Product	Versions
symfony	ux	>= 3.0.0, < 3.1.0>= 2.22.0, < 2.36.0

Weakness: CWE-352 · 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

References

https://github.com/symfony/ux/security/advisories/GHSA-4m4j-hmqq-3gxm x_refsource_CONFIRM
https://github.com/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27 x_refsource_MISC
https://github.com/symfony/ux/releases/tag/v2.36.0 x_refsource_MISC
https://github.com/symfony/ux/releases/tag/v3.1.0 x_refsource_MISC