CVE-2026-49215 json
Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted
published 2026-06-19 4 mo ago modified 2026-10-24 15 d ago also GHSA-4m4j-hmqq-3gxm , EUVD-2026-45218
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- packagist symfony/ux-live-component 2.36.0, 3.1.0
- symfony ux 2.36.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 2.1 | 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 |
| CNA | 4.0 | 2.1 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | symfony/ux-live-component | >=2.22.0, <2.36.0 >=3.0.0, <3.1.0 |
2.36.0 3.1.0 |
Affected products
- symfony ux
Classification
- Weakness
-
- CWE-352 Cross-Site Request Forgery
References
-
github.com
/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27
web, patch
-
github.com
/symfony/ux/security/advisories/GHSA-4m4j-hmqq-3gxm
web, vendor-advisory
-
github.com
/symfony/ux/releases/tag/v2.36.0
release-notes
-
github.com
/symfony/ux/releases/tag/v3.1.0
release-notes
-
github.com
/FriendsOfPHP/security-advisories/blob/master/symfony/ux-live-component/CVE-2026-49215.yaml
web
-
github.com
/symfony/ux
package
Sources
- CVE List CVE-2026-49215
- GitHub Advisory GHSA-4m4j-hmqq-3gxm
- NVD CVE-2026-49215
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