CVE-2026-102266High· 7.4▾ MidnightPoC availablePyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare_key validation. This occurs when a t…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 40.7 · likelihood 0 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 29.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
Exploit / PoC code exists
Last analysed / modified upstream
0.2% → 0.2%
PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from_jwk is affected because PyJWK verification path used the decoded key without applying prepare_key validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As a result, an attacker signs an HMAC token with the same zero-length key accepted by PyJWT. Consequently, forged token can carry arbitrary authenticated claims. This issue is fixed in version 2.14.0.
pyjwt = 2.13.0Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Affected packages:
PyJWT >= 2.13.0, < 2.14.0Patched in:
PyJWT 2.14.0Source: https://github.com/advisories/GHSA-9j54-fg26-wv3r
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-102275Medium· 6.5PyJWT is a Python implementation of JSON Web Token standards
CVE-2026-102271High· 7.4PyJWT is a Python implementation of JSON Web Token standards
CVE-2026-102272High· 7.4PyJWT is a Python implementation of JSON Web Token standards
CVE-2026-102268Critical· 9.1PyJWT is a Python implementation of JSON Web Token standards
CVE-2026-102273High· 7.4PyJWT is a Python implementation of JSON Web Token standards
CVE-2026-103001Medium· 6.5PyJWT is a Python implementation of JSON Web Token standards