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CVE-2026-35042

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

Description (CNA)

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 (CNA)

Vendor / productVersions
nearform / fast-jwtaffected <= 6.1.0

CWE

CWE-345, CWE-636

References

ADP enrichment

CISA-ADP

No English description supplied.