CVE-2026-4636

HIGH8.1EPSS 0.01%

Keycloak: UMA Policy Resource Injection Allows Unauthorized Cross-User Permission Grants

Published: 4/2/2026Modified: 4/4/2026

Description

A flaw was found in Keycloak. An authenticated user with the uma_protection role can bypass User-Managed Access (UMA) policy validation. This allows the attacker to include resource identifiers owned by other users in a policy creation request, even if the URL path specifies an attacker-owned resource. Consequently, the attacker gains unauthorized permissions to victim-owned resources, enabling them to obtain a Requesting Party Token (RPT) and access sensitive information or perform unauthorized actions.

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1HIGH8.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References (10)