User Impersonation Affecting joserfc package, versions [,1.7.4)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-JOSERFC-21193773
- published18 Oct 2026
- disclosed15 Oct 2026
- creditPetr Messner
Introduced: 15 Oct 2026
NewCVE-2026-102946 (opens in a new tab)How to fix?
Upgrade joserfc to version 1.7.4 or higher.
Overview
Affected versions of this package are vulnerable to User Impersonation via verify_general_json in src/joserfc/_rfc7515/json.py, where an attacker can submit a General JSON Serialization JWS object with an empty signatures array to bypass signature verification entirely. Because the function iterates over the signatures list without first checking that it is non-empty, a payload with no signatures passes verification and is accepted as valid, allowing full authentication and integrity bypass.