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.

CVSS v3 4.2 MEDIUM

4.2^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 0.5 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required HIGH

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
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

Configurations

Configuration 1 (hide)

cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*

History

No history.

Information

Published : 2026-04-09 16:16

Updated : 2026-06-17 10:40

NVD link : CVE-2026-35041

Mitre link : CVE-2026-35041

CVE.ORG link : CVE-2026-35041

JSON object : View

Products Affected

nearform

fast-jwt

CWE

CWE-1333

Inefficient Regular Expression Complexity

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