CVE-2026-4636

HIGH

Keycloak UMA Policy - Unauthorized Resource Access

Title source: manual
STIX 2.1

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.

References (6)

Core 6
Core References
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:6475
https://access.redhat.com/errata/RHSA-2026:6475
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:6476
https://access.redhat.com/errata/RHSA-2026:6476
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:6477
https://access.redhat.com/errata/RHSA-2026:6477
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:6478
https://access.redhat.com/errata/RHSA-2026:6478
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-4636
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2450251
https://bugzilla.redhat.com/show_bug.cgi?id=2450251

Scores

CVSS v3 8.1
EPSS 0.0001
EPSS Percentile 2.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-551
Status published
Products (12)
org.keycloak/keycloak-services 0 - 26.5.7Maven
Red Hat/Red Hat build of Keycloak 26.2 26.2-18
Red Hat/Red Hat build of Keycloak 26.2 26.2.15-1
Red Hat/Red Hat build of Keycloak 26.2.15
Red Hat/Red Hat build of Keycloak 26.4 26.4-14
Red Hat/Red Hat build of Keycloak 26.4 26.4.11-1
Red Hat/Red Hat build of Keycloak 26.4.11
redhat/build_of_keycloak
redhat/build_of_keycloak 26.2
redhat/build_of_keycloak 26.2.15
... and 2 more
Published Apr 02, 2026
Tracked Since Apr 02, 2026