redhat build-keycloak CVE-2026-15571 vulnerability in Red Hat Products
Published on August 18, 2026

Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client
A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.

Vendor Advisory Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-15571 can be exploited with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public. 42 days later.

Weakness Type

Predictable from Observable State

A number or object is predictable based on observations that the attacker can make about the state of the system or network, such as time, process ID, etc.


Products Associated with CVE-2026-15571

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Red Hat Build Keycloak
 
Red Hat Jboss Data Grid
 
Red Hat Jbosseapxp
 
Red Hat Single Sign On
 

Affected Versions

Red Hat build of Keycloak 26.6: Red Hat build of Keycloak 26.6: Red Hat build of Keycloak 26.6: Red Hat build of Keycloak 26.6.6: Red Hat build of Keycloak 26.6.6: Red Hat build of Keycloak 26.6.6: Red Hat Data Grid 8: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat Single Sign-On 7: