PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.
References
| Link | Resource |
|---|---|
| https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07 | Patch |
| https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 | Product Release Notes |
| https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 | Exploit Vendor Advisory |
| https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 | Exploit Vendor Advisory |
Configurations
History
07 Oct 2026, 20:25
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Pyjwt Project pyjwt
Pyjwt Project |
|
| References | () https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07 - Patch | |
| References | () https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 - Product, Release Notes | |
| References | () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 - Exploit, Vendor Advisory | |
| CPE | cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:* |
29 Sep 2026, 14:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9 - |
28 Sep 2026, 21:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-28 21:17
Updated : 2026-10-07 20:25
NVD link : CVE-2026-102268
Mitre link : CVE-2026-102268
CVE.ORG link : CVE-2026-102268
JSON object : View
Products Affected
pyjwt_project
- pyjwt
CWE
CWE-347
Improper Verification of Cryptographic Signature
