CVE-2026-18967 — Keycloak-services: keycloak-services: saml onetimeuse assertion replay in idp-initiated broker flow
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 fa…
Published: 2026-08-06 · CVSS: 6.4 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7