Improper access control in Keycloak - CVE-2026-3429
Published: September 10, 2026
Vulnerability identifier: #VU148935
CSH Severity: Low
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-3429
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to take over an account.
The vulnerability exists due to improper access control in the Keycloak Account REST API when performing sensitive MFA credential actions from a lower-security session. A remote user can delete a victim\'s registered MFA/OTP credential and register an attacker-controlled MFA device to take over an account.
Exploitation requires possession of the victim\'s password.
Affected software
Keycloak
Red Hat build of Keycloak
Red Hat build of Keycloak
How to mitigate CVE-2026-3429
Install security update from vendor's website.
Keycloak - update to 26.5.7
Red Hat build of Keycloak - update to 26.4.11
Red Hat build of Keycloak - update to 26.4.11