CVE-2026-19607 vulnerability in Red Hat Products
Published on September 16, 2026
Keycloak-services: keycloak-services: broker-originated username collision causes account lockout
A flaw was found in the first-broker-login flow of the keycloak-services component. This component handles the initial authentication and account linking when a user logs in via an external identity provider. The issue allows an attacker to register a matching username on an external provider to trigger a collision in Keycloak, which results in the legitimate user being locked out of their account.
Vulnerability Analysis
CVE-2026-19607 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Timeline
Reported to Red Hat.
Made public. 36 days later.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-19607 has been classified to as an authentification vulnerability or weakness.
Products Associated with CVE-2026-19607
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Affected Versions
Red Hat build of Keycloak 26.4:- Version 26.4.16-2 and below * is unaffected.
- Version 26.4-26 and below * is unaffected.
- Version 26.4-26 and below * is unaffected.
- Version 26.6.7-3 and below * is unaffected.
- Version 26.6-20 and below * is unaffected.
- Version 26.6-20 and below * is unaffected.