CVE-2026-107723

high

Assigned by CNA: github_m

Published 2026-10-08 · Modified 2026-10-08

Discuss on Community Propose mitigation

CVSS v3

8.1

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

8.1

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts a validly signed JWT whose payload is a JSON array because src/decoder.js checks that the payload is an object but does not reject arrays. The claim validator loop then finds no named exp, nbf, iss, aud, sub, jti, or nonce properties and silently skips those configured checks, returning the array as a successfully verified payload. An attacker who can produce or influence a validly signed token may bypass expiry, issuer, audience, subject, revocation, and replay protections. The opt-in requiredClaims option can block missing claims, and signature verification itself is not bypassed. This issue is fixed in version 6.3.0.

Predictions

Exploit likelihood

88%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-1287

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.