CVE-2026-35042fast-jwt provides fast JSON Web Token (JWT) implementation.
Updated under an hour ago ()
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It affects nearform fast-jwt. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weakness (CWE)
- CWE-345, CWE-636
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
nearform fast-jwt nearform:fast-jwt | before 6.2.0 | NVD |
References
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6exploit, mitigation, vendor-advisory
- https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11technical-description
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.