Description
A flaw was found in the SAML implementation of Keycloak, an open-source identity and access management solution. The SAML Artifact Resolution and ECP SOAP endpoints do not properly limit the size or complexity of incoming XML requests. An unauthenticated remote attacker can exploit this by sending specially crafted, large XML messages that cause the server to consume excessive memory. This leads to the application running out of memory and crashing, resulting in a denial of service for all users.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.17 | — | — |
| Red Hat | Red Hat build of Keycloak 26.6 | — | — |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — |
Advisories 1
- WID-SEC-2026-4375 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
References
- RHSA-2026:95759 vendor-advisory
- RHSA-2026:95760 vendor-advisory
- RHSA-2026:95761 vendor-advisory
- RHSA-2026:95762 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-82965 vdb-entry
- RHBZ#2526302 issue-tracking