Astro is a web framework. Prior to 6.1.6, the defineScriptVars function in Astro's server-side rendering pipeline uses a case-sensitive regex /<\/script>/g to sanitize values injected into inline <script> tags via the define:vars directive. HTML parsers close <script> elements case-insensitively and also accept whitespace or / before the closing >, allowing an attacker to bypass the sanitization with payloads like </Script>, </script >, or </script/> and inject arbitrary HTML/JavaScript. This vulnerability is fixed in 6.1.6.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff Exploit, Mitigation, Vendor Advisory
- https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 6.1 · astroNVD modified 2026-10-26 22:10
Affected (CPE criteria) 1
cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:*
References 2
- https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff Exploit, Mitigation, Vendor Advisory
- https://github.com/withastro/astro/security/advisories/GHSA-j687-52p2-xcff Exploit, Mitigation, Vendor Advisory