CVE-2026-102272High· 7.4▾ MidnightPoC availablePyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before check…
▾ 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.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with a UTF-8 BOM and used in a mixed-algorithm verification path. As a result, public JWK bypasses asymmetric-key detection and becomes the HMAC secret. Consequently, an attacker who knows the public key can forge authenticated tokens. 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 = 2.13.0Patched in:
PyJWT 2.14.0Source: https://github.com/advisories/GHSA-r6x4-923q-g947
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
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