CVE-2026-126361
Astro: XSS via attribute injection in dynamic tag names
Astro is a web framework for content-driven websites. Prior to 7.4.5, Astro rendered a string used as a dynamic element name as raw HTML after applying an incomplete character filter. A / in the string could make an HTML parser treat the remainder as attributes, allowing untrusted element-name input to inject event-handler markup. The .astro dynamic-tag renderer, JSX renderer, and MDX renderer were affected, and exploitation required an application to use request-controlled or stored untrusted data as all or part of an element name. This issue is fixed in version 7.4.5.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| astro withastro |
< 7.4.5 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 2.3 low |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/withastro/astro/security/advisories/GHSA-mh32-jxcr-mh9fCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/withastro/astro/pull/18520CNA: GitHub_M · x_refsource_MISC
- https://github.com/withastro/astro/commit/e023abac912d7cb6af2b9fb5107ef5dabc667096CNA: GitHub_M · x_refsource_MISC
- https://github.com/withastro/astro/releases/tag/[email protected]CNA: GitHub_M · x_refsource_MISC
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