CVE-2026-35042

7.5 HIGH
Published: April 06, 2026 Modified: April 10, 2026
View on NVD

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 ยง4.1.11. 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.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory
https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11
Source: security-advisories@github.com
Technical Description
https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Mitigation Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.0%
5th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

nearform