CVE-2026-102946 (GCVE-0-2026-102946)
Vulnerability from cvelistv5 – Published: 2026-10-15 18:28 – Updated: 2026-10-15 19:53
VLAI
EPSS
VEX
Title
joserfc: JWS signature verification bypass via empty signatures array in jws.deserialize_json
Summary
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.4, joserfc.jws.deserialize_json() accepts a JWS General JSON Serialization with an empty signatures array as authenticated. The verify_general_json() loop performs no iterations for the empty array and returns success because no signature check failed, allowing an attacker without a signing key to supply an arbitrary payload that relying applications may treat as authentic. The issue affects the General JSON Serialization path; compact JWS and JWT decoding, Flattened JSON serialization, and JWE JSON processing do not follow this vulnerable path. This issue is fixed in version 1.7.4.
Severity
9.1 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-15 19:52 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/authlib/joserfc/security/advis… | x_refsource_CONFIRM |
| https://github.com/authlib/joserfc/commit/f409f8f… | x_refsource_MISC |
| https://github.com/authlib/joserfc/releases/tag/1.7.4 | x_refsource_MISC |
Impacted products
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