Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-101918

CVE-2026-101918HIGH

jpadilla pyjwt — PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False)

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0029   19.9     —

AFFECTED
  Product  Versions                Fixed
  pyjwt    >= 2.0.0a1, < 2.15.0 –  —

TIMELINE
  Sep 28  Reserved by GitHub_M
  Sep 28  Published (CNA: GitHub_M)
  Oct 7   EXPLOIT PUBLISHED — CVE-2026-101918 (jpadilla pyjwt). Public exploit reference added.
  Oct 7   RESCORED — CVE-2026-101918 (jpadilla pyjwt). CVSS 5.3 → 7.5 (NVD).

CWE-248 · CNA: GitHub_M · CVSS v3.1 · 3 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
September 28, 2026	Reserved	Reserved by GitHub_M
September 28, 2026	Published	Published (CNA: GitHub_M)
October 7, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-101918 (jpadilla pyjwt). Public exploit reference added.
October 7, 2026	RESCORED	RESCORED — CVE-2026-101918 (jpadilla pyjwt). CVSS 5.3 → 7.5 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
jpadilla	pyjwt	—	>= 2.0.0a1, < 2.15.0	—

Weaknesses

CWE-248

References (3)

https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b [Patch]
https://github.com/jpadilla/pyjwt/releases/tag/2.15.0 [Product, Release Notes]
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-101918 at cve.org

Vendors: jpadilla

Weaknesses: CWE-248

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-101918 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Thursday, October 8, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.