CVE-2026-117691: Red Hat Build of Keycloak (Critical, CVSS 9.1)

What it is

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.

Description from the National Vulnerability Database.

What to do

Check whether you run Red Hat Build of Keycloak, then apply the vendor’s fix or mitigation from the advisories below.

Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.