Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.16 | — | — |
| Red Hat | Red Hat build of Keycloak 26.6 | — | — |
| Red Hat | Red Hat build of Keycloak 26.6.7 | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-keycloak | No fix yet | — |
| Ubuntu 24.04 LTS | python-keycloak | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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7Ragnarok7/CVE-2026-19607 ★ 3 · Aug 8, 2026
Vulnerability Details and Exploit for CVE-2026-19607
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- WID-SEC-2026-3418 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 17, 2026
References
- RHSA-2026:68276 vendor-advisory
- RHSA-2026:68277 vendor-advisory
- RHSA-2026:68278 vendor-advisory
- RHSA-2026:68280 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-19607 vdb-entry
- RHBZ#2514529 issue-tracking