CVE-2026-18967

HIGH CVSS 3.1: 8.1 EPSS 0.14%
Updated Aug 10, 2026
Red Hat
Parameter Value
CVSS 8.1 (HIGH)
Type CWE-294 (Authentication Bypass by Capture-Replay)
Vendor Red Hat
Public PoC No

A flaw was found in the SAML broker component of Keycloak, an identity and access management solution. When configured as a SAML broker using the IdP-Initiated flow, Keycloak fails to enforce the OneTimeUse condition in SAML assertions. This allows an attacker who captures a valid, unused assertion to replay it multiple times.

Successful exploitation could allow an attacker to hijack a user's session and gain unauthorized access to the system as that user.

Attack Parameters

Attack Vector
Adjacent
Requires local network access
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption

CVSS Vector v3.1

Vulnerable Products 2

Configuration From (including) Up to (excluding)
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*
Redhat Jboss_Enterprise_Application_Platform_Expansion_Pack
cpe:2.3:a:redhat:jboss_enterprise_application_platform_expansion_pack:-:*:*:*:*:*:*:*