CVE-2026-49210
MEDIUMSymfony UX: XSS in symfony/ux-live-component via attacker-controlled child component tag
Title source: cnaDescription
Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Util\ChildComponentPartialRenderer::createHtml() interpolates the client-controlled children[id].tag value from LiveComponentSubscriber and InterceptChildComponentRenderSubscriber directly into HTML as a tag name without escaping or validation, allowing arbitrary HTML, including <script> tags, on any Live Component re-render that contains at least one child component. This issue is fixed in versions 2.36.0 and 3.1.0.
References (4)
Core 4
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/symfony/ux/security/advisories/GHSA-38x5-rcv4-xf7x
X_Refsource_Misc x_refsource_misc
https://github.com/symfony/ux/commit/fbc5e9a1bda7e4556be21bb1d970f382760ed9a9
X_Refsource_Misc x_refsource_misc
https://github.com/symfony/ux/releases/tag/v2.36.0
X_Refsource_Misc x_refsource_misc
https://github.com/symfony/ux/releases/tag/v3.1.0
Scores
CVSS v3
6.1
EPSS
0.0019
EPSS Percentile
9.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Products (4)
symfony/ux
3.0.0
symfony/ux
2.8.0 - 2.36.0
symfony/ux
>= 2.8.0, < 2.36.0
symfony/ux
>= 3.0.0, < 3.1.0
Published
Jul 17, 2026
Tracked Since
Jul 17, 2026