Description
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.
Affected products
astro: astro
References2
- github.com/withastro/astro/security/advisories/GHSA-j687-52p2-x… ExploitMitigationVendor Advisory
- github.com/withastro/astro/security/advisories/GHSA-j687-52p2-x… ExploitMitigationVendor Advisory
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 9 · as of 13 November 2026
- CWE
- CWE-79
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