CVE-2026-110024: @fastify/jwt Insufficient Session Expiration

Vulnerability summary

CVE-2026-110024 is a medium (CVSS 6.8) Insufficient Session Expiration vulnerability in @fastify/jwt. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.8% of scored vulnerabilities.

Timeline

1. 18-10-2026
   PublishedVulnerability first disclosed.
2. 20-10-2026
   Last modifiedVulnerability information updated.

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.

• CWE-613Insufficient Session ExpirationAccording to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."