{"id":"CVE-2026-102266","title":"PyJWT is a Python implementation of JSON Web Token standards","summary":"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 t…","severity":"high","cvss":7.4,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-347"],"vendor":"pyjwt_project","product":"pyjwt","affected":["pyjwt = 2.13.0"],"patched":["PyJWT 2.14.0"],"published":"2026-09-28","updated":"2026-10-07","sourceUpdated":"2026-10-07T20:55:07.653","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-102266","references":[{"url":"https://github.com/jpadilla/pyjwt/commit/f91ed44dd65baaf457f4b3353ed35e98a753934c","label":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/releases/tag/2.14.0","label":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r","label":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102266.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-102266"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2542671"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-102266"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102266"},{"url":"https://github.com/advisories/GHSA-9j54-fg26-wv3r"},{"url":"https://github.com/jpadilla/pyjwt"},{"url":"https://pypi.org/project/pyjwt"},{"url":"https://access.redhat.com/errata/RHSA-2026:82415"},{"url":"https://access.redhat.com/errata/RHSA-2026:82368"},{"url":"https://access.redhat.com/errata/RHSA-2026:82061"},{"url":"https://access.redhat.com/errata/RHSA-2026:82059"},{"url":"https://access.redhat.com/errata/RHSA-2026:82371"},{"url":"https://access.redhat.com/errata/RHSA-2026:87004"},{"url":"https://access.redhat.com/errata/RHSA-2026:87120"},{"url":"https://access.redhat.com/errata/RHSA-2026:87124"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat","ghsa","pip","osv"],"epss":0.00225,"epssPercentile":0.13049,"aliases":["GHSA-9j54-fg26-wv3r","PYSEC-2026-4143"],"ecosystem":"pip","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-09-29T19:28:36.086597Z"},"ingestedAt":"2026-09-28T21:20:54.779Z","slug":"CVE-2026-102266","body":"## Overview\n\nPyJWT 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.\n\n## Affected\n\n- `pyjwt = 2.13.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-102266)\n\nAffected packages:\n\n- `PyJWT >= 2.13.0, < 2.14.0`\n\nPatched in:\n\n- `PyJWT 2.14.0`\n\nSource: https://github.com/advisories/GHSA-9j54-fg26-wv3r\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Ansible Automation Orchestrator 2026, Fence Agents Remediation Operator, Migration Toolkit for Applications 8, Red Hat Ansible Automation Platform 2, Red Hat Ceph Storage 4, Red Hat Ceph Storage 7, … · no fix planned: Red Hat Ceph Storage 4, Red Hat Ceph Storage 7, Red Hat Ceph Storage 9, Ansible Automation Orchestrator 2026, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102266.json)\n- **RHSA-2026:82415** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82415)\n- **RHSA-2026:82368** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82368)\n- **RHSA-2026:82061** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82061)\n- **RHSA-2026:82059** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82059)\n- **RHSA-2026:82371** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82371)\n- **RHSA-2026:87004** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.6 for RHEL 9 · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87004)\n- **RHSA-2026:87120** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.6 · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87120)\n- **RHSA-2026:87124** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.7 · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87124)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":40.7,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":213117,"id":"CVE-2026-102266","ts":1790714815829,"field":"exploit_available","old":"false","new":"true"}]}