Vulnerability Description
Astro is a web framework for content-driven websites. Versions prior to 7.0.6 are vulnerable to XSS through unescaped spread attribute names in renderHTMLElement. The fix for CVE-2026-54298 (GHSA-jrpj-wcv7-9fh9) added an INVALID_ATTR_NAME_CHAR guard to addAttribute() so that spread-prop attribute names containing "' >/= or whitespace are dropped. A second attribute-rendering path, renderHTMLElement() in packages/astro/src/runtime/server/render/dom.ts, has its own inline attribute loop that does not go through addAttribute() and was not updated. It interpolates the attribute name unescaped and only escapes the value, so untrusted prop keys spread onto a native-HTMLElement-subclass component can still break out of the attribute context. This issue has been fixed in version 7.0.6.
Related Weaknesses (CWE)
References
- https://github.com/withastro/astro/commit/5240e26c9dd91f9bc7140dcfacdb48d5a13283
- https://github.com/withastro/astro/pull/17251
- https://github.com/withastro/astro/releases/tag/[email protected]
- https://github.com/withastro/astro/security/advisories/GHSA-f48w-9m4c-m7f5
- https://github.com/withastro/astro/security/advisories/GHSA-f48w-9m4c-m7f5
FAQ
What is CVE-2026-59729?
CVE-2026-59729 is a documented vulnerability. Astro is a web framework for content-driven websites. Versions prior to 7.0.6 are vulnerable to XSS through unescaped spread attribute names in renderHTMLElement. The fix for CVE-2026-54298 (GHSA-jrpj...
How severe is CVE-2026-59729?
CVSS scoring is not yet available for CVE-2026-59729. Check NVD for updates.
Is there a patch for CVE-2026-59729?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.