CVE-2026-3429: Org.keycloak.services.resources.account: improper access control leading to mfa deletion and account takeover in keycloak account rest api
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.
Other sources
Improper Access Control vulnerability in the Account REST API of Keycloak. The flaw is caused by insufficient validation of the authentication Level of Assurance (LoA) before allowing credential management actions. An attacker who has obtained a victim’s primary credentials (username and password) can authenticate at a lower LoA and delete the victim’s registered OTP/MFA credential without completing step-up authentication. The attacker can then register their own MFA device, effectively achieving full account takeover. Exploitation requires network access and valid credentials but no user interaction, resulting in compromise of account integrity and partial confidentiality impact.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3429?
CVE-2026-3429 is classified as a critical severity vulnerability that allows for improper access control, potentially leading to account takeover.
How do I fix CVE-2026-3429?
To mitigate CVE-2026-3429, upgrade Keycloak to version 26.5.6 or later, which addresses the access control vulnerability.
What type of vulnerability is CVE-2026-3429?
CVE-2026-3429 is an improper access control vulnerability affecting the Keycloak Account REST API.
What actions are impacted by CVE-2026-3429?
CVE-2026-3429 allows users authenticated at lower security levels to delete multi-factor authentication settings and perform sensitive actions.
What software versions are affected by CVE-2026-3429?
CVE-2026-3429 affects Keycloak versions up to and including 26.5.5.