CVE-2026-107719

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

4.2CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 19% of CVEs (scores of 2026-10-25)

CWE

CWE-613

Published

2026-10-08

Modified

2026-10-09

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://github.com/nearform/fast-jwt/commit/fc1ddbbe5ce38066ba2cea0b0ce0233932757167
• https://github.com/nearform/fast-jwt/releases/tag/v6.3.4
• https://github.com/nearform/fast-jwt/security/advisories/GHSA-x937-hj6v-793p
• https://github.com/nearform/fast-jwt/security/advisories/GHSA-x937-hj6v-793p

Check your stackJSON