Improper Authentication Affecting joserfc package, versions <1.6.8-1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.14% (5th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-JOSERFC-18015554
  • published19 Jul 2026
  • disclosed17 Jul 2026

Introduced: 17 Jul 2026

CVE-2026-49852  (opens in a new tab)
CWE-287  (opens in a new tab)
CWE-326  (opens in a new tab)
CWE-1391  (opens in a new tab)

How to fix?

Upgrade Debian:unstable joserfc to version 1.6.8-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream joserfc package and not the joserfc package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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 Base Scores

version 3.1