Home

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC.

PUBLISHED Reserved 2026-03-31 | Published 2026-04-06 | Updated 2026-04-07 | Assigner GitHub_M




HIGH: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Problem types

CWE-345: Insufficient Verification of Data Authenticity

CWE-636: Not Failing Securely ('Failing Open')

Product status

<= 6.1.0
affected

References

github.com/...st-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6 exploit

github.com/...st-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6

www.rfc-editor.org/rfc/rfc7515.html

cve.org (CVE-2026-35042)

nvd.nist.gov (CVE-2026-35042)

Download JSON