Red Hat Build of Keycloak/Single Sign-On SAML XML Processing resource consumption

Summaryinfo

A vulnerability classified as problematic has been found in Red Hat Build of Keycloak and Single Sign-On. This affects an unknown part of the component SAML XML Processing. This manipulation causes resource consumption. This vulnerability is handled as CVE-2026-107123. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Red Hat Build of Keycloak and Single Sign-On (version now known). It has been declared as problematic. Affected by this vulnerability is some unknown processing of the component SAML XML Processing. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

A flaw was found in the SAML XML processing component of Keycloak, an open-source identity and access management solution. The issue occurs when the server parses XML documents containing excessively long dateTime or duration values. Because these strings are not properly validated before processing, the XML parser consumes excessive CPU time. An unauthenticated remote attacker can exploit this by sending specially crafted SAML requests to the server, leading to high CPU utilization and a denial of service for all users.

The advisory is shared at access.redhat.com. This vulnerability is known as CVE-2026-107123 since 10/07/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/05/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Red Hat

Name

• Build of Keycloak
• Single Sign-On

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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