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.
History

Sat, 07 Nov 2026 15:45:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak:
References

Sat, 07 Nov 2026 15:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak:26.6::el9
References

Fri, 06 Nov 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Thu, 05 Nov 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 05 Nov 2026 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Red Hat
Red Hat red Hat Build Of Keycloak 26.4
Redhat build Of Keycloak
Redhat single Sign-on
Vendors & Products Red Hat
Red Hat red Hat Build Of Keycloak 26.4
Redhat build Of Keycloak
Redhat single Sign-on

Thu, 05 Nov 2026 13:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Keycloak-services: keycloak-services: saml redirect binding signature bypass via percent-encoded parameter names
First Time appeared Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
Weaknesses CWE-347
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published: 2026-11-05T13:27:23.748Z

Updated: 2026-11-07T15:39:27.366Z

Reserved: 2026-10-27T13:49:55.445Z

Link: CVE-2026-117691

cve-icon Vulnrichment

Updated: 2026-11-05T16:28:29.946Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-11-05T14:17:01.320

Modified: 2026-11-07T16:16:39.990

Link: CVE-2026-117691

cve-icon Redhat

Severity : Important

Publid Date: 2026-11-05T00:00:00Z

Links: CVE-2026-117691 - Bugzilla