CVE-2026-107275
MediumCVSS 6.8Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
@fastify/jwt is a JSON Web Token plugin for Fastify. In versions before 10.2.3, a time span passed to expiresIn, notBefore, or maxAge that the parser cannot read is silently dropped instead of refused. This produces tokens with no expiration on signing, and on verification maxAge stops being enforced, so tokens that should be rejected are accepted. The issue is fixed in 10.2.3.
Risk Assessment
JWT tokens may never expire, allowing prolonged access to resources, and token age verification may be bypassed, increasing the risk of unauthorized access.
Recommendation
Upgrade @fastify/jwt to 10.2.3 or later. As a workaround, pass time options as seconds or validate time-span strings before relying on them.
Other vulnerabilities in @fastify/jwt
See all- CVE-2026-110024Medium
@fastify/jwt versions prior to 10.2.5 have top-level sign and verify methods that replace globally configured defaults with per-call options instead of merging them. This silently drops temporal protections such as token expiration and maximum accepted token age, so tokens never expire.
- CVE-2026-18500High
In @fastify/jwt, a JSON Web Token plugin for Fastify, versions before 10.2.2, a per-request verification key passed to request.jwtVerify({ key }) is silently overridden by the plugin's globally configured secret. Applications using different keys for different authorization domains may accept tokens signed with the global key on routes requiring another key, allowing an ordinary authenticated user to cross a key-based trust boundary. The issue is fixed in version 10.2.2.
Original NVD description (English source)
@fastify/jwt is a JSON Web Token plugin for the Fastify web framework. In versions before 10.2.3, a time span passed to expiresIn, notBefore, or maxAge that the plugin's parser cannot read, such as a compound span, a month unit, an ISO 8601 duration, a decimal comma, or a value with surrounding whitespace, is silently dropped instead of refused. On the signing path this produces a token with no expiration claim that never expires, and on the verification path a configured maxAge stops being enforced, so a token that should be rejected for age is accepted. The issue is fixed in @fastify/jwt 10.2.3, and users should upgrade to 10.2.3 or later. As a workaround, pass these options as a number of seconds, or verify that any time-span string parses to a finite value before relying on it.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS