7.5

CVE-2026-35042

Exploit

fast-jwt accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Nearform ≫ Fast-jwt SwPlatformnode.js Version < 6.2.0
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.16% 0.05
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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.

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