CVE-2026-49852

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.

CVSS

No CVSS.

References

Link	Resource
https://github.com/authlib/joserfc/commit/86d00910b2b2d2d07503fee9b572906daefab7f1
https://github.com/authlib/joserfc/releases/tag/1.6.8
https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh
https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-17 20:17

Updated : 2026-07-23 18:02

NVD link : CVE-2026-49852

Mitre link : CVE-2026-49852

CVE.ORG link : CVE-2026-49852

JSON object : View

Products Affected

No product.

CWE

CWE-287

Improper Authentication

CWE-326

Inadequate Encryption Strength

CWE-1391

Use of Weak Credentials

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