CVE-2026-103001 (GCVE-0-2026-103001)

Vulnerability from cvelistv5 – Published: 2026-09-30 21:15 – Updated: 2026-10-05 23:47
VLAI
Title
PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse
Summary
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.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-05 23:47 UTC
CWE
  • CWE-471 - Modification of Assumed-Immutable Data (MAID)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8029 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
jpadilla pyjwt Affected: >= 2.11.0, <= 2.13.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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