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CVE-2026-120459 Details

Description

python-jose through 3.5.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge JWTs because HMACKey and CryptographyHMACKey accept zero-length HMAC secrets. When an application's HS256/HS384/HS512 verification key resolves to empty, such as an oct JWK with empty k, attackers can forge tokens with arbitrary claims that jwt.decode accepts.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:7.4 HIGHVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/cryptography_backend.py	[email protected]
https://github.com/mpdavis/python-jose/blob/3.5.0/jose/backends/native.py	[email protected]
https://github.com/mpdavis/python-jose/issues/398	[email protected]
https://www.vulncheck.com/advisories/python-jose-through-3.5.0-authentication-bypass-via-empty-hmac-key	[email protected]

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-347	Improper Verification of Cryptographic Signature	[email protected]

Affected Products

No affected product data is available for this CVE.

Change History

1 change record found show changes