CVE-2026-3429: Org.keycloak.services.resources.account: improper access control leading to mfa deletion and account takeover in keycloak account rest api

Severity: medium (CVSS 4.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-11 · updated 2026-08-18
Weakness: CWE-284

Description

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 26.4: from 26.4 before 26.4.11 — fixed in 26.4.11

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.4.11. Check the vendor advisory for mitigations.

References

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