CVE-2026-18967

medium

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.

References

https://bugzilla.redhat.com/show_bug.cgi?id=2511604

https://access.redhat.com/security/cve/CVE-2026-18967

Details

Source: Mitre, NVD

Published: 2026-08-06

Updated: 2026-08-06

Risk Information

CVSS v2

Base Score: 6.2

Vector: CVSS2#AV:A/AC:H/Au:N/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 6.4

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

Severity: Medium

EPSS

EPSS: 0.00143