Description
@fastify/jwt is a JWT utility plugin for Fastify. In versions prior to 10.2.5, the top-level sign and verify methods replace the globally configured defaults with the per-call options instead of merging them, so passing any per-call option silently drops every global default that the call does not restate, including temporal protections such as token expiration and maximum accepted token age. A token signed this way carries no expiration claim and never expires, and verification stops enforcing a configured maximum age, so stale or never-expiring tokens are accepted. The route-level decorators for signing and verifying already merge options and are not affected. The issue is fixed in @fastify/jwt 10.2.5, and users should upgrade to 10.2.5 or later.
References2
Metrics
- CVSS 3.1
-
6.8
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 8 · as of 10 November 2026
- CWE
- CWE-613
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.