CVE-2026-35039
Critical · 9.1CVSS
9.1
EPSS
0.2%
Published
Apr 6, 2026
CISA due date
—
The record
fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cause tokens to be mis-identified during the verification process leading to valid tokens returning claims from different valid tokens and users being mis-identified as other users based on the wrong token. Version 6.2.0 contains a patch.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | fast-jwt | 0.0.1 | 6.2.0 |
Related vulnerabilities
- GHSA-rp9m-7r4c-75qg fast-jwt: Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a… Same vulnerability
- CVE-2026-44351 fast-jwt provides fast JSON Web Token (JWT) implementation. Also affects fast-jwt
- GHSA-gmvf-9v4p-v8jc fast-jwt: JWT auth bypass due to empty HMAC secret accepted by async key resolver Also affects fast-jwt
- GHSA-cjw9-ghj4-fwxf fast-jwt has a ReDoS when using RegExp in allowed* leading to CPU exhaustion during token… Also affects fast-jwt
- GHSA-3j8v-cgw4-2g6q fast-jwt: Stateful RegExp (/g or /y) causes non-deterministic allowed-claim validation… Also affects fast-jwt
- CVE-2026-35040 fast-jwt provides fast JSON Web Token (JWT) implementation. Also affects fast-jwt
- CVE-2026-35041 fast-jwt provides fast JSON Web Token (JWT) implementation. Also affects fast-jwt
- CVE-2026-35042 fast-jwt provides fast JSON Web Token (JWT) implementation. Also affects fast-jwt