7.5 High

CVE-2026-107602 Keycloak-services: keycloak-services: unauthenticated cpu exhaustion via saml 1.1 keyinfo infinite loop

Description

A flaw was found in the SAML 1.1 XML parsing logic of Keycloak, an open-source identity and access management solution. The issue occurs when the parser encounters unexpected elements within a security token's key information section, causing the processing thread to enter an infinite loop. An unauthenticated remote attacker could exploit this by sending specially crafted requests, leading to 100% CPU usage and a total denial of service that requires a server restart to resolve.

CVSS 3.1 detail

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

Exploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Network
Attack complexity: Low
Privileges required: None
Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Affected products and versions

Product	Affected versions	Fixed in
Red Hat Build of Keycloak	Versions not published
Red Hat Single Sign-On 7	Versions not published

References

access.redhat.com access.redhat.com
RHBZ#2547937 bugzilla.redhat.com

Timeline

Published November 5, 2026
Last modified November 5, 2026

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