fast-jwt: Stateful RegExp (/g or /y) causes non-deterministic allowed-claim validation (logical DoS) (nearform fast-jwt)

CVE-2026-35040
MEDIUM 5.3

En bref

Source
NVD
EPSS
EPSS 0.38 % · centile 32 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
GitHub_M
Statut NVD
Analyzed

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unintended behaviours. This is because some modifiers are stateful and will cause failures in every second verification attempt regardless of the validity of the token provided. Such modifiers are /g (global matching) and /y (sticky matching). This does NOT allow invalid tokens to be accepted, only for valid tokens to be improperly rejected in some configurations. Instead it causes 50% of valid authentication requests to fail in an alternating pattern. This vulnerability is fixed in 6.2.1.

Faiblesses (CWE)

  • CWE-697 — Comparaison incorrecte
  • CWE-440 — Expected Behavior Violation

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LGitHub_M
CVSS 3.1MEDIUM 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LNVD · security-advisories@github.com (Secondary)

Avis

Références européennes

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
nearform · fast-jwtaffected < 6.2.1

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD