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Fencer Vulns
medium 4.4

CVE-2026-102270 json

PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.

published 2026-09-28 41 d ago modified 2026-10-06 33 d ago also GHSA-jwrc-g2q2-pq5p , PYSEC-2026-4148 , EUVD-2026-88537

cvss
4.4
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 15%
public exploits
0
none known

Summary

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. 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-2026-102270

  • python-PyJWT SLE Module for Public Cloud 12 1.5.3-3.22.1
  • python-PyJWT SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +9 more 2.8.0-150400.8.20.1
  • python-PyJWT Linux Micro 6.1 2.12.1-slfo.1.1_3.1
  • python-PyJWT SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 2.12.1-160000.3.1
  • python-PyJWT Linux Micro 6.0 2.9.0-159998.1.1

suse advisories SUSE-SU-2026:5093-1SUSE-SU-2026:5064-1SUSE-SU-2026:24377-1SUSE-SU-2026:24126-1SUSE-SU-2026:24219-1SUSE-SU-2026:24134-1

  • python-PyJWT openSUSE Leap 16.0 2.12.1-160000.3.1
  • python-PyJWT openSUSE Tumbleweed 2.15.1-1.1

opensuse advisories openSUSE-SU-2026:22074-1openSUSE-SU-2026:11994-1

  • python-jwt Azure Linux 3.0 2.15.1-1

azure linux advisories AZL-104988

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

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-2026-102270 updated cvss 4.4

pyjwt: pyjwt: Denial of Service via regular expression backtracking in is_pem_format

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-backend-rhel9 Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-podvm-builder-rhel9 Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel9-operator 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 Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9 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
    +14 more products
    Red Hat AI Inference Server rhaiis/vllm-cuda-rhel9, rhaiis/vllm-rocm-rhel9 Red Hat Ansible Automation Platform 2 python3.12-pyjwt, automation-controller, ansible-automation-platform-25/hub-rhel8, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform-25/gateway-rhel8, +22 more 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 Red Hat Enterprise Linux 9 fence-virt, fence-virtd, fence-agents, fence-virtd-cpg, fence-virtd-tcp, fence-agents-all, +51 more Red Hat Enterprise Linux 10 fence-agents-common Red Hat OpenShift AI (RHOAI) rhoai/odh-ogx-core-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-feature-server-rhel9, rhoai/odh-llm-d-kv-cache-rhel9, +22 more Red Hat OpenShift Container Platform 5 python-pyjwt Red Hat OpenShift Virtualization 4 openshift-virtualization/konflux-builds/v4-22/ocp-virt-validation-checkup-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 python-pyjwt, python3-pyjwt, python3.12-pyjwt, satellite/foreman-mcp-server-rhel9 Red Hat Trusted Artifact Signer rhtas/segment-reporting-rhel9, rhtas/model-transparency-rhel9 Red Hat Update Infrastructure 5 rhui5/rhua-rhel9, rhui5/rhua-tp-rhel9
    affected: workaround, no fix available “Fix deferred”
  • 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 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 AI Inference Server rhaii/vllm-tpu-rhel9, rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9, rhaii/vllm-neuron-rhel9 Red Hat Ansible Automation Platform 2 python-pyjwt, python3x-pyjwt, python3.11-pyjwt, ansible-automation-platform-24/hub-rhel8, ansible-automation-platform-24/controller-rhel8, ansible-automation-platform-24/lightspeed-rhel8, +4 more Red Hat Enterprise Linux 8 python-jwt, python3-jwt, rhel8/support-tools Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-gaudi-rhel9 Red Hat Enterprise Linux command line assistant rhel-cla/rhel-knowledge-bridge-rhel10
    not affected: vulnerable code not present
  • Red Hat Hardened Images rust 1.98.1-1.hum1, llvm21 21.1.8-10.hum1, jaeger 2.20.0-0.11.hum1, swift-lang 6.4.0-0.5.hum1
    not affected: component not present
  • Red Hat OpenStack Platform 13 (Queens) python-jwt Red Hat OpenStack Platform 16.2 rhosp-rhel8/openstack-tempest, rhosp-rhel8/openstack-keystone, rhosp-rhel8/openstack-cinder-api, rhosp-rhel8/openstack-mistral-api, rhosp-rhel8/openstack-mistral-base, rhosp-rhel8/openstack-mistral-engine, +2 more Red Hat OpenStack Platform 17.1 python3-jwt, rhosp-rhel9/openstack-keystone, rhosp-rhel9/openstack-cinder-api Red Hat OpenStack Platform 18.0 python-jwt, rhoso/openstack-keystone-rhel9, rhoso/openstack-cinder-api-rhel9 Red Hat Satellite 6 satellite/iop-host-inventory-rhel9 Red Hat Update Infrastructure 4 for Cloud Providers python-pyjwt
    not affected: vulnerable code not present

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
partial
Assessed
40 d ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5p referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi pyjwt
<2.14.0
2.14.0

Affected products

  • jpadilla pyjwt

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Vulns 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.