---
id: CVE-2026-101917
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,
  PyJWT get_signing_key_from_jwt is affected because unknown kid misses force
  refreshes without a negative cache or minimum refresh interval. This occurs
  when u…
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-770
vendor: jpadilla
product: pyjwt
affected:
  - pyjwt < 2.14.0
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T21:17:13.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101917'
references:
  - url: >-
      https://github.com/jpadilla/pyjwt/commit/ba4853a75fb9676362da17f67d0f64bd18afd4e1
    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-2gx3-rcp4-g85q'
    label: security-advisories@github.com
  - url: 'https://github.com/jpadilla/pyjwt/security/advisories/GHSA-2gx3-rcp4-g85q'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-28T20:35:19.525335Z'
ingestedAt: '2026-09-28T21:20:54.777Z'
---

## Overview

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT get_signing_key_from_jwt is affected because unknown kid misses force refreshes without a negative cache or minimum refresh interval. This occurs when unauthenticated tokens repeatedly use the same unknown kid or varying kid values absent from the cached JWKS. As a result, each cache miss causes PyJWKClient to refresh the JWKS. Consequently, attacker traffic can amplify outbound requests to the configured JWKS endpoint. This issue is fixed in version 2.14.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.