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
redhat: build of keycloak
References4
- access.redhat.com/errata/RHSA-2026:6477 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:6478 Vendor Advisory
- access.redhat.com/security/cve/CVE-2026-3429 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2443771 Issue TrackingVendor Advisory
Metrics
- CVSS 3.1
-
4.2
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 20 · as of 12 November 2026
- CWE
- CWE-284
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.