CVE-2026-107275

Status: Awaiting AnalysisMedium (6.8)—

@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.

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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.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Base score: 6.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.31%
Percentile among all scored CVEs: 23
Score date: 10/17/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1210 Exploitation of Remote Serviceslateral movement75 %
Primary impactT1078 Valid Accountsstealth · persistence · privilege escalation · initial access80 %
Secondary impactT1556 Modify Authentication Processdefense impairment · persistence · credential access70 %

Acceso remoto con privilegios (PR:L) a servicio web Fastify. Impacto: tokens JWT sin expiración permiten autenticación persistente y secuestro de identidad.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management User Account Management Password Policies Multi-factor Authentication Application Developer Guidance Active Directory Configuration

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Fastify — Fastify JWT^AI

CWEs

CWE-390, CWE-613, CWE-754

References

Raw JSON (NVD)

Show

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