Cloudanix VulnDB

CVE-2026-103001

Medium · 6.5

CVSS

6.5

EPSS

0.2%

Published

Sep 30, 2026

CISA due date

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The record

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.

Affected packages

Ecosystem Package Introduced Fixed

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