CVE-2026-3429: Red Hat Build Of Keycloak

Medium severity, CVSS 4.2. EPSS: 0.3% chance of exploitation in the next 30 days.

A flaw was identified in the Account REST API of Keycloak that allows a user authenticated at a lower security level to perform sensitive actions intended only for higher-assurance sessions. Specifically, an attacker who has already obtained a victim’s password can delete the victim’s registered MFA/OTP credential without first proving possession of that factor. The attacker can then register their own MFA device, effectively taking full control of the account. This weakness undermines the intended protection provided by multi-factor authentication.

Affected products

• Red Hat Build Of Keycloak: from 26.4, before 26.4.11 (fixed in 26.4.11)

Published 2026-03-11. Last modified 2026-08-18.