Medium severity · published Jul 17, 2026
CVE-2026-49215
Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted
5.4
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UX
ux · symfony
>= 3.0.0, < 3.1.0; >= 2.22.0, < 2.36.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-49215
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-49215
Patch
https://github.com/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27
Release Notes
https://github.com/symfony/ux/releases/tag/v2.36.0
Release Notes
https://github.com/symfony/ux/releases/tag/v3.1.0
Vendor Advisory
https://github.com/symfony/ux/security/advisories/GHSA-4m4j-hmqq-3gxm
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