Vulnerability details

CVE-2026-117691

Red Hat Build of Keycloak

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

CVSS 3.1
9.1Critical

Official 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.

CVSS scores

ScoreVersionSourceVector
9.1Critical 3.1 CVEProject cvelistV5 (CNA) (redhat) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

VendorProductVersionsSource
Red Hat Red Hat Build of Keycloak All CVEProject cvelistV5 (CNA)

References and advisories

3
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Details

Published
2026-11-05
Last updated
2026-11-07
State
Published
Assigner (CNA)
redhat
Kolun priority
25 · Low

Exploit prediction (EPSS)

0.28%
Probability of exploitation in 30 days
20.8%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
None
Technical impact
Total

Weaknesses (CWE)

  • CWE-347
    Improper Verification of Cryptographic Signature