CVE-2026-35041

fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.

The following products are affected by CVE-2026-35041 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-35041.

URL	Resource
https://github.com/nearform/fast-jwt/commit/b0be0ca161593836a153d5180ca5358ad9b5de94
https://github.com/nearform/fast-jwt/pull/595
https://github.com/nearform/fast-jwt/releases/tag/v6.2.1
https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf