Vulnerability · Published Aug 5, 2026 · Assigned by redhat
CVE-2026-16442Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction
High 7.4
In plain English
A high-severity security flaw in Red Hat build of Keycloak 26.4 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Official description
A flaw was found in the SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4.14 | see references |
| Red Hat | Red Hat build of Keycloak 26.4.14 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat Data Grid 8 | see references |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | see references |
| Red Hat | Red Hat Single Sign-On 7 | see references |
Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- RHSA-2026:50846 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50847 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50848 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50849 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-16442 vdb-entry, x_refsource_REDHAT
- RHBZ#2503138 issue-tracking, x_refsource_REDHAT