CVE-2026-35042
7.5
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Exploitability: 3.9 / Impact: 3.6
Source: security-advisories@github.com (Secondary)
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.
Affected (1)
Related CWEs
CWE-345
Insufficient Verification of Data Authenticity
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
CWE-636
Not Failing Securely ('Failing Open')
When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.
References (3)
Source: security-advisories@github.com
ExploitMitigationVendor Advisory
Source: security-advisories@github.com
Technical Description
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
ExploitMitigationVendor Advisory
Timeline
No history available yet.