by Kastro CVE-2026-117691
Red Hat Red Hat Build of Keycloak — Keycloak-services: keycloak-services: saml redirect binding signature bypass via percent-encoded parameter names
Description · from the CVE record
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
Affected
ProductAffectedFixed inSource
Red Hat Build of Keycloaksee advisory–CNA
Red Hat Build of Keycloaksee advisory–CNA
Red Hat Single Sign-On 7see advisory–CNA
Scores by source
redhat (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total