CVE Vulnerabilities

CVE-2026-102266

Improper Verification of Cryptographic Signature

Published: Sep 28, 2026 | Modified: Oct 07, 2026
CVSS 3.x
9.1
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
7.4 IMPORTANT
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Ubuntu
MEDIUM
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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.

Weakness

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Software

NameVendorStart VersionEnd Version
PyjwtPyjwt_project2.13.0 (including)2.13.0 (including)
Red Hat Ansible Automation Platform 2.6 for RHEL 9RedHatpython3.12-pyjwt-0:2.14.0-1.el9ap*
Red Hat AI Inference Server 3.5RedHatrhaii/vllm-rocm-rhel9:1791425869*
Red Hat AI Inference Server 3.5RedHatrhaii/vllm-gaudi-rhel9:1791427182*
Red Hat AI Inference Server 3.5RedHatrhaii/vllm-cuda-rhel9:1791473631*
Red Hat AI Inference Server 3.5RedHatrhaii/vllm-spyre-rhel9:1791818357*
Red Hat AI Inference Server 3.5RedHatrhaii/vllm-cpu-rhel9:1791473614*
Red Hat Ansible Automation Platform 2.6RedHatansible-automation-platform-26/ee-supported-rhel9:1791974220*
Red Hat Ansible Automation Platform 2.6RedHatansible-automation-platform-26/gateway-rhel9:1791971533*
Red Hat Ansible Automation Platform 2.6RedHatansible-automation-platform-tech-preview/metrics-service-rhel9:1791944819*
Red Hat Ansible Automation Platform 2.7RedHatansible-automation-platform-27/gateway-rhel9:1792429216*
Red Hat Ansible Automation Platform 2.7RedHatansible-automation-platform-27/metrics-service-rhel9:1792387216*
PyjwtUbunturesolute*
PyjwtUbuntustonking*
PyjwtUbuntuupstream*

References