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CVE-2026-35041

CVE-2026-35041 · ReDoS in fast-jwt when using RegExp in allowed* leading to CPU exhaustion during token verification

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 4.2 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • fast-jwt

    Versions
    • >= 5.0.0, < 6.2.1: Affected

    No fix published

  • fast-jwt npm

    Affected ranges
    • SEMVER: ≥ 5.0.0, < 6.2.1

    Update to 6.2.1

Original sources

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