---
id: CVE-2026-102268
title: PyJWT is a Python implementation of JSON Web Token standards
summary: >-
  PyJWT 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 not
  recognize every PEM representation accepted by the cryptography loader. This
  occurs w…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-347
vendor: pyjwt_project
product: pyjwt
affected:
  - pyjwt < 2.14.0
patched:
  - pyjwt 2.14.0
published: '2026-09-28'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T20:25:03.030'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102268'
references:
  - url: >-
      https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07
    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-ffc3-869f-jxw9'
    label: security-advisories@github.com
  - url: 'https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102268'
  - url: 'https://github.com/advisories/GHSA-ffc3-869f-jxw9'
  - url: 'https://github.com/jpadilla/pyjwt'
  - url: 'https://pypi.org/project/pyjwt'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102268.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-102268'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2542685'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-102268'
  - 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-2026:84785'
tags:
  - nvd
  - exploit-available
  - cve.org
  - ghsa
  - pip
  - osv
  - csaf
  - vex
  - red-hat
epss: 0.00236
epssPercentile: 0.14689
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/covepseng/cve-2026-102268-poc'
  checkedAt: '2026-11-05T15:27:30.898Z'
exploitAvailable: true
aliases:
  - GHSA-ffc3-869f-jxw9
  - PYSEC-2026-4145
ecosystem: pip
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-29T13:59:05.202281Z'
ingestedAt: '2026-09-28T21:20:54.780Z'
---

## Overview

PyJWT 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 not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.

## Affected

- `pyjwt < 2.14.0`

## Remediation

Upgrade past the affected range:

- `pyjwt 2.14.0`

## Package advisory (CVE-2026-102268)

Affected packages:

- `PyJWT <= 2.13.0`

Patched in:

- `PyJWT 2.14.0`

Source: https://github.com/advisories/GHSA-ffc3-869f-jxw9

## Vendor advisories

- **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)
- **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)
- **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)
- **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)
- **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)
- **Red Hat VEX** · Critical · affected: Lightspeed Core, Red Hat Ansible Automation Platform 2, Red Hat Ceph Storage 4, Red Hat Ceph Storage 7, Red Hat Ceph Storage 9, Red Hat Enterprise Linux 10, … · no fix planned: Red Hat Ceph Storage 4, Red Hat Ceph Storage 7, Red Hat Ceph Storage 9, Lightspeed Core, … · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102268.json)
- **RHSA-2026:84785** · Red Hat · fixed in: Red Hat Trusted Artifact Signer 1.4 · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84785)