CVE-2026-18967 — MEDIUM (6.4)

Vulnerability Description

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.

CVSS Score

6.4

MEDIUM

CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector

ADJACENT_NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Related Weaknesses (CWE)

CWE-294

References

FAQ

What is CVE-2026-18967?

CVE-2026-18967 is a vulnerability with a CVSS score of 6.4 (MEDIUM). 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 OneT...

How severe is CVE-2026-18967?

CVE-2026-18967 has been rated MEDIUM with a CVSS base score of 6.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-18967?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.