AIKIDO-2026-533631
@clerk/astro is vulnerable to Cross-site Scripting (XSS)
71
High Risk
This Affects:
@clerk/astroTL;DR
Affected versions of this package are vulnerable to stored Cross-site Scripting (XSS). Clerk auth state is serialized with JSON.stringify into SSR <script> tags. User-controllable session claims containing a </script> sequence can break out of the script element and execute arbitrary JavaScript in the browser. The fix escapes <, >, and / (and Unicode line terminators) so the embedded JSON remains safe while parsing to identical values on the client.
Who does this affect?
You are affected if you use @clerk/astro within the vulnerable range and render SSR pages that embed Clerk auth state, especially when session claims can contain user-controlled values.
Background info
@clerk/astro is vulnerable to Cross-site Scripting (XSS) in versions 0.0.1 - 3.4.18.
How to fix this
Upgrade the @clerk/astro library to the patch version.
Are You Affected?
Connect your repositories to instantly see whether vulnerable or malicious packages exist in your codebase.
Free. No credit card required.
I consent to receiving marketing communications based on Aikido’s Privacy Policy.
SOC 2Compliant
ISO 27001Compliant