CVE-2026-102273
PyJWT accepts public JWK containers as HMAC secrets
CVSS Score
7.4
EPSS Score
0.0%
EPSS Percentile
0th
PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because HMAC key guard only recognizes top-level public JWK forms and misses container representations. This occurs when an application allows HMAC and asymmetric algorithms and passes a public JWK container as the raw key. As a result, public asymmetric key material is accepted as the HMAC secret. Consequently, an attacker who knows the public key can forge a token with arbitrary authenticated claims. This issue is fixed in version 2.14.0.
| CWE | CWE-347 |
| Vendor | jpadilla |
| Product | pyjwt |
| Published | Sep 28, 2026 |
Stay Ahead of the Next One
Get instant alerts for jpadilla pyjwt
Be the first to know when new high vulnerabilities affecting jpadilla pyjwt are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
jpadilla / pyjwt
>= 2.13.0, < 2.14.0