CVE-2026-16442
This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.20% probability · 10th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-346
- Affected
- redhat/build of keycloak
- Source
- secalert@redhat.com
References
- https://access.redhat.com/errata/RHSA-2026:50846Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50847Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50848Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50849Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-16442Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2503138Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.