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
redhat: build of keycloak
References6
- access.redhat.com/errata/RHSA-2026:50846 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50847 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50848 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50849 Vendor Advisory
- access.redhat.com/security/cve/CVE-2026-16442 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2503138 Issue TrackingVendor Advisory
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 25 · as of 13 November 2026
- CWE
- CWE-346
Could this be exploited in your environment?
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