← Vulnerability feed

Vulnerability record · CVE-2026-102273 · published 28 September 2026

CVE-2026-102273: Pyjwt project pyjwt improper verification of cryptographic signature vulnerability

Pyjwt Project · Pyjwt

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.

7.4 CVSS 3.1 High EPSS 0.18% · top 93.7% CWE-347 · Improper verification of cryptographic signature
7.4CVSS 3.1 base score
0.18%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References
6 Oct 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/jpadilla/pyjwt/commit/801cd128528c62d9b23fcd161d1a2e1c17982f95 Patch
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0 ProductRelease Notes
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w2cx-738m-mc7w Vendor Advisory

Track CVE-2026-102273 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2026-102266Pyjwt project pyjwt improper verification of cryptographic signature vulnerabilityPyJWT 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…EPSS 0.18%9.1CVE-2026-102267Pyjwt project pyjwt information exposure vulnerabilityPyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not re…EPSS 0.16%9.1CVE-2026-102268Pyjwt project pyjwt improper verification of cryptographic signature vulnerabilityPyJWT 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 n…EPSS 0.20%8.2CVE-2026-102275Pyjwt project pyjwt insufficient verification of data authenticity vulnerabilityPyJWT is a Python implementation of JSON Web Token standards. From 2.1.0 until 2.15.0, PyJWT OKPAlgorithm.from_jwk in jwt/algorithms.py is affected b…EPSS 0.14%7.5CVE-2026-102274Pyjwt project pyjwt vulnerabilityPyJWT is a Python implementation of JSON Web Token standards. From 2.9.0 until 2.14.0, PyJWKSet does not catch the plain ValueError raised for malfor…EPSS 0.39%7.5CVE-2026-101918Pyjwt project pyjwt vulnerabilityPyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected becau…EPSS 0.36%7.5CVE-2026-101917Pyjwt project pyjwt allocation without limits vulnerabilityPyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT get_signing_key_from_jwt is affected because unknown kid misses …EPSS 0.42%7.5CVE-2026-32597Pyjwt project pyjwt insufficient verification of data authenticity vulnerabilityPyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does not validate the crit (Critical) Header Parameter defined in RFC 7515…EPSS 0.28%

Source: NIST National Vulnerability Database (record CVE-2026-102273), CISA KEV, FIRST EPSS (scores of 2026-10-08). This page is refreshed as NVD updates the record.