AIKIDO-2026-517140
@clerk/tanstack-react-start is vulnerable to Cross-site Scripting (XSS)
71
High Risk
This Affects:
@clerk/tanstack-react-startTL;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, so a </script> sequence in user-controllable session claims can break out of the script element and execute attacker-controlled JavaScript. The patch escapes <, >, and / (via htmlSafeJson) while preserving identical JSON.parse values on the client.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range.
Background info
@clerk/tanstack-react-start is vulnerable to Cross-site Scripting (XSS) in versions 0.0.1 - 1.4.19.
How to fix this
Upgrade the @clerk/tanstack-react-start 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 27001CompliantISO 42001Compliant
FedRAMPImplementing© All Intel data is openly available and commercially licensed.