Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-103001

CVE-2026-103001MEDIUM

jpadilla pyjwt — PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   H   N   N  U  L  H  N    6.5   .0024   14.2     —

AFFECTED
  Product  Versions                Fixed
  pyjwt    >= 2.11.0, <= 2.13.0 –  —

TIMELINE
  Sep 29  Reserved by GitHub_M
  Sep 30  Published (CNA: GitHub_M)
  Oct 8   EXPLOIT PUBLISHED — CVE-2026-103001 (jpadilla pyjwt). Public exploit reference added.

CWE-471 · CNA: GitHub_M · CVSS v3.1 · 3 references · NVD status: Analyzed

Description

PyJWT is a Python implementation of JSON Web Token standards. From 2.11.0 through 2.13.0, PyJWT's PyJWT._merge_options() method can modify a caller-supplied mutable options mapping when verify_signature is false. If an application reuses that same mapping for a later decode() or decode_complete() call and changes verify_signature to true, the mapping can retain false values for expiration, not-before, issued-at, audience, issuer, subject, and JWT ID checks. A signed token with invalid registered claims can then be accepted without disabling signature verification, but applications that create a fresh options mapping for each call are not affected.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 29, 2026	Reserved	Reserved by GitHub_M
September 30, 2026	Published	Published (CNA: GitHub_M)
October 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-103001 (jpadilla pyjwt). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
jpadilla	pyjwt	—	>= 2.11.0, <= 2.13.0	—

Weaknesses

CWE-471

References (3)

https://github.com/jpadilla/pyjwt/commit/0c87c8c8b1a74cac99ad8115f3050efcb7fbed35 [Patch]
https://github.com/jpadilla/pyjwt/issues/679 [Exploit, Issue Tracking]
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-gvp8-978c-rx2q [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-103001 at cve.org

Vendors: jpadilla

Weaknesses: CWE-471

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-103001 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 Monday, October 19, 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.