Astro is a web framework. Prior to 6.3.3, when a component uses a client:* directive, Astro inserts named slot content into a data-astro-template attribute without HTML escaping the slot name allowing an attacker to break out of the attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp Exploit, Mitigation, Vendor Advisory
- https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp 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 2026-10-25 23:10
Affected (CPE criteria) 1
cpe:2.3:a:astro:astro:*:*:*:*:*:node.js:*:*
References 2
- https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp Exploit, Mitigation, Vendor Advisory
- https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp Exploit, Mitigation, Vendor Advisory