---
id: CVE-2026-101918
title: PyJWT is a Python implementation of JSON Web Token standards
summary: >-
  PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1
  until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because
  payload parser catches ValueError but not RecursionError. This occurs when an
  attacke…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-248
vendor: pyjwt_project
product: pyjwt
affected:
  - 'pyjwt >= 2.0.0, < 2.15.0'
patched:
  - pyjwt 2.15.0
published: '2026-09-28'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T20:59:17.860'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101918'
references:
  - url: >-
      https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b
    label: security-advisories@github.com
  - url: 'https://github.com/jpadilla/pyjwt/releases/tag/2.15.0'
    label: security-advisories@github.com
  - url: 'https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-101918.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-101918'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2542668'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-101918'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101918'
  - url: 'https://github.com/advisories/GHSA-42vr-xj54-vc7v'
  - 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'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
  - ghsa
  - pip
  - osv
epss: 0.00413
epssPercentile: 0.35394
aliases:
  - GHSA-42vr-xj54-vc7v
  - PYSEC-2026-4141
ecosystem: pip
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-29T13:55:59.459735Z'
ingestedAt: '2026-09-28T21:20:54.778Z'
---

## Overview

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.

## Affected

- `pyjwt >= 2.0.0, < 2.15.0`

## Remediation

Upgrade past the affected range:

- `pyjwt 2.15.0`

## Package advisory (CVE-2026-101918)

Affected packages:

- `PyJWT >= 2.0.0a1, <= 2.14.0`

Patched in:

- `PyJWT 2.15.0`

Source: https://github.com/advisories/GHSA-42vr-xj54-vc7v

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Ansible Automation Orchestrator 2026, Confidential Compute Attestation, Fence Agents Remediation Operator, Lightspeed Core, Migration Toolkit for Applications 8, OpenShift Lightspeed, … · no fix planned: Ansible Automation Orchestrator 2026, Confidential Compute Attestation, Fence Agents Remediation Operator, Lightspeed Core, … · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-101918.json)
- **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)