CVE-2026-35042

HIGH EPSS 5.1%
Published Apr 6, 20262mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Apr 6, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
5.1% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 2

CWE-345
CWE-636

Affected Products 1

VendorProductVersionRange
nearformfast-jwt* <6.2.0

References 2

  • github.com https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6
    ExploitMitigationVendor Advisory
  • rfc-editor.org https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11
    Technical Description

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.