Advisory record · GHSA-w6j9-cwv2-h6wq

PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set

CVSS 5.9 MediumEPSS 0.0055 · 46th percentile

Published by the GitHub Advisory Database at 29 Sept 2026, 18:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
pyjwtPyPI>=2.9.0, <2.14.02.14.0
Identifiers
GHSA-w6j9-cwv2-h6wq · CVE-2026-102274 · PYSEC-2026-4152
Weakness (CWE)
CWE-755
Published
29 Sept 2026
Updated
1 Oct 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

PyJWT versions from 2.9.0 up to but not including 2.14.0 are affected. A malformed RSA JWK inside a JWK Set, with an invalid private exponent and no CRT parameters, raises a plain ValueError that PyJWKSet does not catch, so parsing of the whole set aborts and later valid keys are not loaded. An attacker would need a malformed key to already be present in a set the application parses; the result is an availability failure, not a signature bypass. Upgrade to PyJWT 2.14.0.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
5.9 Medium 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0055, the 46th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:09 UTC First seen by agentprime
  2. 31 Oct 2026, 14:09 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.