Mend.io Vulnerability Database
The largest open source vulnerability database
What is a Vulnerability ID?
New vulnerability? Tell us about it!
CVE-2026-4636
Published:April 02, 2026
Updated:April 20, 2026
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
https://github.com/keycloak/keycloak.git (GITHUB):
Affected version(s) >=26.5.0 <26.5.7
Fix Suggestion:
Update to version 26.5.7
https://github.com/keycloak/keycloak.git (GITHUB):
Affected version(s) >=26.2.0 <26.2.15
Fix Suggestion:
Update to version 26.2.15
https://github.com/keycloak/keycloak.git (GITHUB):
Affected version(s) >=26.4.0 <26.4.11
Fix Suggestion:
Update to version 26.4.11
org.keycloak:keycloak-services (JAVA):
Affected version(s) >=1.0-alpha-1 <26.5.7
Fix Suggestion:
Update to version 26.5.7
org.keycloak:keycloak-services (JAVA):
Affected version(s) >=26.5.0 <26.5.7
Fix Suggestion:
Update to version 26.5.7
Do you need more information?
Contact Us
CVSS v4
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
EPSS
Base Score:
0.03