Is CVE-2026-35042 actively exploited?

No active exploitation of CVE-2026-35042 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-35042 be exploited remotely?

Yes. CVE-2026-35042 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-35042?

CVE-2026-35042 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-35042

HIGH

CVE-2026-35042

CWE-345Published: April 6, 2026· Updated: Apr 10, 2026

7.5

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:2.8th

Official 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.

NVD Source

Technical Analysis

CVE-2026-35042 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.