Description


fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts Infinity for clockTolerance because its option validation checks type and negativity but not finiteness. In validateClaimDateValue, infinite positive and negative modifiers make exp and nbf comparisons always pass, allowing expired or not-yet-active tokens to be accepted. The verifier cache also derives infinite bounds, so entries created under this configuration can remain valid until eviction. Exploitation requires an application administrator or equivalent configuration path to set clockTolerance to Infinity. This issue is fixed in version 6.3.0.

Related CPE's


Could not find any relations

Weaknesses



CWE-613CWE-682

CVSS impact metrics


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

5.9 · Medium

Information


Source identifier

[email protected]

Vulnerability status

Deferred

Published

2026-10-08T22:17:28.263Z

10 hours ago

Last modified

2026-10-08T22:17:28.410Z

10 hours ago