CVE-2026-117691criticalCWE-347

CVE-2026-117691: critical vulnerability in Red Hat build of Keycloak 26.6

Keycloak-services: keycloak-services: saml redirect binding signature bypass via percent-encoded parameter names

Published · Updated

Follow this CVE+ Monitor Red Hat build of Keycloak+ Monitor Red Hat Single Sign-On

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

48Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 9.1epss 0.3%
from disclosure to weapon2 days
Published on NVDNov 5
1st PoC+2d
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected products
Red Hat · Red Hat build of Keycloak 26.6Red Hat · Red Hat build of Keycloak 26.6.9Red Hat · Red Hat Single Sign-On 7
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — Red Hat build of Keycloak 26.6

In the same product, most dangerous first.

CVE-2026-18963CRITICALKeycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypassEPSS 4.7%CVE-2023-5685HIGHXnio: stackoverflowexception when the chain of notifier states becomes problematically bigEPSS 3.5%CVE-2024-3656HIGHKeycloak: unguarded admin rest api endpoints allows low privilege users to use administrative functionalitiesEPSS 3.3%CVE-2024-5971HIGHUndertow: response write hangs in case of java 17 tlsv1.3 newsessionticketEPSS 2.9%CVE-2026-93567HIGHIo.netty/netty-codec-http2: http/1 authority-form connect is translated to malformed http/2 connect with host-controlled :authorityEPSS 2.9%CVE-2026-76166MEDIUMModcluster-core: mod_cluster advertise listener: unauthenticated dos via crafted multicast datagramEPSS 2.7%