A flaw was found in Keycloak’s CIBA feature where insufficient validation of client-configured backchannel notification endpoints could allow blind server-side requests to internal services.

Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. After further review by the Keycloak project and Red Hat, the reported SSRF via client registration/backchannel notification URIs was determined not to constitute a security vulnerability. The reported behavior is expected administrator-controlled functionality, and Keycloak provides documented mitigations through Client Policies, including the Secure Client URIs Pattern executor. Therefore, this CVE has been rejected.

Red Hat, Inc.: AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

Red Hat, Inc.: CWE-918

Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-1518

Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2433727

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{"timestamp":"2026-02-02T14:03:51.798430Z","id":"CVE-2026-1518","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

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A flaw was found in Keycloak’s CIBA feature where insufficient validation of client-configured backchannel notification endpoints could allow blind server-side requests to internal services.

AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

CWE-918

https://access.redhat.com/security/cve/CVE-2026-1518

https://bugzilla.redhat.com/show_bug.cgi?id=2433727