CVE-2026-107719
mediumfast-jwt provides fast JSON Web Token (JWT) implementation.
fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.4, the fast-jwt createVerifier cache can continue accepting a previously valid, signed JWT after its exp time when caching is enabled and the token has exp but no iat. In src/verifier.js, cacheSet derives the exp cache deadline only when iat is present, so the cache falls back to cacheTTL, and a later cache hit returns the saved payload before verifyToken rechecks expiration. An attacker who can replay the same cached bearer token can extend access until the cache entry expires, but cannot forge a token through this issue. This issue is fixed in version 6.3.4.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/nearform/fast-jwt/commit/fc1ddbbe5ce38066ba2cea0b0ce0233932757167 security-advisories@github.com
- https://github.com/nearform/fast-jwt/releases/tag/v6.3.4 security-advisories@github.com
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-x937-hj6v-793p security-advisories@github.com
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-x937-hj6v-793p 134c704f-9b21-4f2e-91b3-4a467353bcc0