CVE-2026-103001

Published: October 5, 2026Last modified: October 7, 2026

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.

Severity score breakdown

ParameterValue
Base score6.5
Attack VectorNETWORK
Attack complexityHIGH
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityLOW
Integrity impactHIGH
Availability impactNONE
VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N

Status

ProductReleasePackageStatus
Alpaquita Linux25 LTSpy3-jwtVulnerable (2.10.1-r0)
Streampy3-jwtVulnerable (2.8.0-r1)

References

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