CVE-2026-102946
joserfc: JWS signature verification bypass via empty signatures array in jws.deserialize_json
- State
- Published
- Severity
- 9.1 Critical
- Published
- Oct 15, 2026
- Updated
- Oct 15, 2026
- Reserved
- Sep 29, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
joserfcauthlib |
|
References
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