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Fencer Intel
high 7.4

CVE-2026-102266 json

PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

published last mo. modified last mo. also EUVD-2026-88484 , GHSA-9j54-fg26-wv3r , PYSEC-2026-4143

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

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 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.

Patch / fix

  • pypi pyjwt 2.14.0
  • pyjwt_project pyjwt 2.14.0
  • pyjwt Debian 14 2.14.0-1

debian advisories DEBIAN-CVE-2026-102266

  • pyjwt Ubuntu 26.10 2.13.0-1ubuntu1
  • pyjwt Ubuntu 26.04 LTS 2.10.1-4ubuntu1.2

ubuntu advisories UBUNTU-CVE-2026-102266

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-PyJWT openSUSE Tumbleweed 2.15.1-1.1

opensuse advisories openSUSE-SU-2026:11994-1

  • fence-virt AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-all AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-apc AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-aws AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-gce AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-rsa AlmaLinux 9 4.10.0-110.el9_8.8
  • ha-cloud-support AlmaLinux 9 4.10.0-110.el9_8.8
  • fence-agents-lpar AlmaLinux 9 4.10.0-110.el9_8.8

almalinux advisories ALSA-2026:94500ALSA-2026:94501

  • fence-agents Rocky Linux 10 4.16.0-21.el10_2.7
  • fence-agents Rocky Linux 9 4.10.0-110.el9_8.8

rocky linux advisories RLSA-2026:94501RLSA-2026:94500

  • python-jwt Azure Linux 3.0 2.15.1-1

azure linux advisories AZL-105239

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-102266 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-102266 updated cvss 7.4

pyjwt: pyjwt: Authentication bypass via empty HMAC key acceptance

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-backend-rhel9 Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel9-operator Red Hat Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform-27/ee-supported-rhel9, ansible-automation-platform-26/eda-controller-rhel9, ansible-automation-platform-27/eda-controller-rhel9
    affected: workaround, no fix available
  • Red Hat Ceph Storage 4 python2-jwt Red Hat Ceph Storage 7 rhceph/rhceph-7-rhel9 Red Hat Ceph Storage 9 rhceph/rhceph-9-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-ogx-core-rhel9, rhoai/odh-feature-server-rhel9, rhoai/odh-th-torch-cuda-py312-rhel9, rhoai/odh-kserve-autogluon-server-rhel9, rhoai/odh-kserve-storage-initializer-rhel9, rhoai/odh-trustyai-garak-lls-provider-dsp-rhel9, +14 more
    affected: workaround, no fix available
  • Red Hat Lightspeed Core lightspeed-core/rag-tool-cpu-rhel9, lightspeed-core/lightspeed-stack-rhel9, lightspeed-core/rag-tool-cuda-12.9-rhel9 Red Hat AI Inference Server rhaii/vllm-tpu-rhel9, rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9, rhaiis/vllm-cuda-rhel9, rhaiis/vllm-rocm-rhel9, rhaii/vllm-neuron-rhel9 Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-gaudi-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-llama-stack-core-rhel9, rhai-early-access/docling-serve-cuda-rhel9 Red Hat Satellite 6 python-pyjwt, python3-pyjwt, python3.12-pyjwt, satellite/foreman-mcp-server-rhel9, satellite/iop-host-inventory-rhel9 Red Hat Trusted Artifact Signer rhtas/rh-sigstore-a2a-rhel9, rhtas/model-transparency-rhel9
    +2 more products
    Red Hat Update Infrastructure 4 for Cloud Providers python-pyjwt Red Hat Update Infrastructure 5 rhui5/rhua-rhel9, rhui5/rhua-tp-rhel9
    under investigation
  • Red Hat AI Inference Server 3.5 rhaii/vllm-cpu-rhel9 1791473614, rhaii/vllm-cuda-rhel9 1791473631, rhaii/vllm-rocm-rhel9 1791425869, rhaii/vllm-gaudi-rhel9 1791427182, rhaii/vllm-spyre-rhel9 1791818357
    fixed: vendor fix RHSA-2026:82415
  • Red Hat Ansible Automation Platform 2.6 ansible-automation-platform-26/gateway-rhel9 1791971533, ansible-automation-platform-26/ee-supported-rhel9 1791974220, ansible-automation-platform-tech-preview/metrics-service-rhel9 1791944819
    fixed: vendor fix RHSA-2026:87120
  • Red Hat Ansible Automation Platform 2.6 for RHEL 9 python3.12-pyjwt 2.14.0-1.el9ap, python3.12-pyjwt+crypto 2.14.0-1.el9ap
    fixed: vendor fix RHSA-2026:87004
  • Red Hat Ansible Automation Platform 2.7 ansible-automation-platform-27/gateway-rhel9 1792429216, ansible-automation-platform-27/metrics-service-rhel9 1792387216
    fixed: vendor fix RHSA-2026:87124
show 13 more
  • Red Hat Enterprise Linux AI 3.5 rhelai3/bootc-cuda-rhel9 1793135861, rhelai3/bootc-rocm-rhel9 1793135863, rhelai3/bootc-aws-cuda-rhel9 1793194817, rhelai3/bootc-gcp-cuda-rhel9 1793194815, rhelai3/disk-image-cuda-rhel9 1793206758, rhelai3/bootc-azure-cuda-rhel9 1793194815, +1 more
    fixed: vendor fix RHSA-2026:92452
  • Red Hat Enterprise Linux AppStream (v. 9) fence-virt 4.10.0-110.el9_8.8, fence-virtd 4.10.0-110.el9_8.8, fence-agents 4.10.0-110.el9_8.8, fence-virtd-cpg 4.10.0-110.el9_8.8, fence-virtd-tcp 4.10.0-110.el9_8.8, fence-agents-all 4.10.0-110.el9_8.8, +51 more
    fixed: vendor fix RHSA-2026:94500
  • Red Hat Enterprise Linux AppStream (v. 10) fence-virt 4.16.0-21.el10_2.7, fence-virtd 4.16.0-21.el10_2.7, fence-agents 4.16.0-21.el10_2.7, fence-virtd-cpg 4.16.0-21.el10_2.7, fence-virtd-tcp 4.16.0-21.el10_2.7, fence-agents-all 4.16.0-21.el10_2.7, +50 more
    fixed: vendor fix RHSA-2026:94501
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) fence-virt 4.10.0-43.el9_2.27, fence-virtd 4.10.0-43.el9_2.27, fence-agents 4.10.0-43.el9_2.27, fence-virtd-cpg 4.10.0-43.el9_2.27, fence-virtd-tcp 4.10.0-43.el9_2.27, fence-agents-virsh 4.10.0-43.el9_2.27, +8 more
    fixed: vendor fix RHSA-2026:94634
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) fence-virt 4.10.0-62.el9_4.31, fence-virtd 4.10.0-62.el9_4.31, fence-agents 4.10.0-62.el9_4.31, fence-virtd-cpg 4.10.0-62.el9_4.31, fence-virtd-tcp 4.10.0-62.el9_4.31, fence-agents-virsh 4.10.0-62.el9_4.31, +8 more
    fixed: vendor fix RHSA-2026:94557
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) fence-virt 4.16.0-5.el10_0.14, fence-virtd 4.16.0-5.el10_0.14, fence-agents 4.16.0-5.el10_0.14, fence-virtd-cpg 4.16.0-5.el10_0.14, fence-virtd-tcp 4.16.0-5.el10_0.14, fence-agents-all 4.16.0-5.el10_0.14, +50 more
    fixed: vendor fix RHSA-2026:95012
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) fence-virt 4.10.0-86.el9_6.23, fence-virtd 4.10.0-86.el9_6.23, fence-agents 4.10.0-86.el9_6.23, fence-virtd-cpg 4.10.0-86.el9_6.23, fence-virtd-tcp 4.10.0-86.el9_6.23, fence-agents-all 4.10.0-86.el9_6.23, +51 more
    fixed: vendor fix RHSA-2026:94523
  • Red Hat Enterprise Linux High Availability E4S (v.9.2) fence-agents-all 4.10.0-43.el9_2.27, fence-agents-apc 4.10.0-43.el9_2.27, fence-agents-aws 4.10.0-43.el9_2.27, fence-agents-eps 4.10.0-43.el9_2.27, fence-agents-gce 4.10.0-43.el9_2.27, fence-agents-rsa 4.10.0-43.el9_2.27, +37 more
    fixed: vendor fix RHSA-2026:94634
  • Red Hat Enterprise Linux High Availability E4S (v.9.4) fence-agents-all 4.10.0-62.el9_4.31, fence-agents-apc 4.10.0-62.el9_4.31, fence-agents-aws 4.10.0-62.el9_4.31, fence-agents-eps 4.10.0-62.el9_4.31, fence-agents-gce 4.10.0-62.el9_4.31, fence-agents-rsa 4.10.0-62.el9_4.31, +37 more
    fixed: vendor fix RHSA-2026:94557
  • Red Hat Enterprise Linux Resilient Storage E4S (v.9.2) fence-agents-all 4.10.0-43.el9_2.27, fence-agents-apc 4.10.0-43.el9_2.27, fence-agents-aws 4.10.0-43.el9_2.27, fence-agents-eps 4.10.0-43.el9_2.27, fence-agents-gce 4.10.0-43.el9_2.27, fence-agents-rsa 4.10.0-43.el9_2.27, +36 more
    fixed: vendor fix RHSA-2026:94634
  • Red Hat Enterprise Linux Resilient Storage E4S (v.9.4) fence-agents-all 4.10.0-62.el9_4.31, fence-agents-apc 4.10.0-62.el9_4.31, fence-agents-aws 4.10.0-62.el9_4.31, fence-agents-eps 4.10.0-62.el9_4.31, fence-agents-gce 4.10.0-62.el9_4.31, fence-agents-rsa 4.10.0-62.el9_4.31, +36 more
    fixed: vendor fix RHSA-2026:94557
  • Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-podvm-builder-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed/lightspeed-agentic-sandbox-rhel9, openshift-lightspeed/lightspeed-to-dataverse-exporter-rhel9 Red Hat Ansible Automation Platform 2 python-pyjwt, python3x-pyjwt, python3.11-pyjwt, automation-controller, ansible-automation-platform-24/hub-rhel8, ansible-automation-platform-25/hub-rhel8, +21 more Red Hat Ansible Automation Platform 2.6 ansible-automation-platform-26/hub-rhel9 1791947385, ansible-automation-platform-26/hub-web-rhel9 1791952205, ansible-automation-platform-26/receptor-rhel9 1791968536, ansible-automation-platform-26/mcp-tools-rhel9 1791941340, ansible-automation-platform-26/controller-rhel9 1791947602, ansible-automation-platform-26/de-minimal-rhel9 1791961810, +22 more Red Hat Ansible Automation Platform 2.6 for RHEL 9 receptor 1.6.9-1.el9ap, molecule 26.10.0-1.el9ap, receptorctl 1.6.9-1.el9ap, ansible-lint 26.10.1-1.el9ap, ansible-rulebook 1.2.3-1.el9ap, automation-hub 4.11.15-1.el9ap, +50 more Red Hat Ansible Automation Platform 2.6 for RHEL 10 receptor 1.6.9-1.el10ap, molecule 26.10.0-1.el10ap, python-cffi 2.0.0-2.el10ap, receptorctl 1.6.9-1.el10ap, python3-cffi 2.0.0-2.el10ap, ansible-lint 26.10.1-1.el10ap, +11 more Red Hat Ansible Automation Platform 2.7 ansible-automation-platform-27/hub-rhel9 1792388670, ansible-automation-platform-27/hub-web-rhel9 1792394496, ansible-automation-platform-27/receptor-rhel9 1792139928, ansible-automation-platform-27/mcp-tools-rhel9 1792425046, ansible-automation-platform-27/controller-rhel9 1792389457, ansible-automation-platform-27/de-minimal-rhel9 1792141111, +25 more
    +2 more products
    Red Hat Enterprise Linux 8 rhel8/support-tools Red Hat Enterprise Linux command line assistant rhel-cla/rhel-knowledge-bridge-rhel10
    not affected: vulnerable code not present

10 more not affected in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi pyjwt
>=2.13.0, <2.14.0
2.14.0

Affected products

  • jpadilla pyjwt

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.