CVSS v3.1
4.2
EPSS
0.26%
Published
Apr 9, 2026
Modified
Apr 14, 2026
Public PoC / Exploit
All weaponized →No public PoC or exploit code indexed for this CVE.
Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
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.
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:HWeaknesses (CWE)
Affected Products (1)
References (5)