CVE-2026-102946

joserfc: JWS signature verification bypass via empty signatures array in jws.deserialize_json

CRITICAL 9.1

En bref

Source: NVD
EPSS: EPSS 0.12 % · centile 2 (2026-10-28)
État: PUBLISHED
Publiée: 2026-10-15 18:28 UTC
Mise à jour: 2026-10-15 19:53 UTC
Attribuée par: GitHub_M
Statut NVD: Deferred

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.

Faiblesses (CWE)

CWE-290 — Contournement d'authentification par usurpation
CWE-345 — Vérification insuffisante de l'authenticité des données
CWE-347 — Vérification incorrecte d'une signature cryptographique

Références

Scores

Version	Score	Vecteur	Évalué par
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	GitHub_M
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	NVD · security-advisories@github.com (Secondary)

Références européennes

ENISA EUVD · EUVD-2026-102310
GCVE · GCVE-0-2026-102946

Produits affectés

Produit	Versions
authlib · joserfc	affected < 1.7.4

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD