Predictable from Observable State in Keycloak - CVE-2026-15571
Published: September 10, 2026
Vulnerability identifier: #VU148959
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-15571
CWE-ID: CWE-341
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to take over a victim's account.
The vulnerability exists due to predictable hash generation in the legacy client-initiated account-linking endpoint when processing account-linking requests. A remote user can trick a user into authenticating and forge a valid linking URL to connect the victim's account to an attacker-controlled external identity to take over a victim's account.
User interaction is required to authenticate.
Affected software
Keycloak
Red Hat build of Keycloak
Red Hat build of Keycloak
How to mitigate CVE-2026-15571
Install security update from vendor's website.
Keycloak - update to 26.7.2
Red Hat build of Keycloak - update to 26.6.6
Red Hat build of Keycloak - update to 26.6.6