CVE-2026-117691
CVE-2026-117691
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Weakness classification (CWE)
References
- access.redhat.com/errata/RHSA-2026:96039 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:96040 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2026-117691 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
Frequently asked questions
- What is CVE-2026-117691?
- CVE-2026-117691 is a critical-severity vulnerability, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.1/10. Published 2026-11-05.
- How severe is CVE-2026-117691?
- Critical severity. CVSS v3 base score is 9.1 out of 10.