CVEvulnerability
CVE-2026-35041
6.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-04-09
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 4.2 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-1333
Description
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.
Affected configurations
• nearform fast-jwt (>= 5.0.0 < 6.2.1)
Related
Weakness · CWE (1)
- CWE-1333 Inefficient Regular Expression Complexity weakness
References
- https://github.com/nearform/fast-jwt/commit/b0be0ca161593836a153d5180ca5358ad9b5de94 Patch
- https://github.com/nearform/fast-jwt/pull/595 Issue Tracking, Patch
- https://github.com/nearform/fast-jwt/releases/tag/v6.2.1 Product, Release Notes
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf Exploit, Mitigation, Vendor Advisory
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf Exploit, Mitigation, Vendor Advisory