Description
A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
Metrics
CVSS 3.1 5.3/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — |
| Red Hat | Red Hat build of Keycloak 26.4 | — |
| Red Hat | Red Hat build of Keycloak 26.4 | — |
| Red Hat | Red Hat build of Keycloak 26.4.10 | — |
| Red Hat | Red Hat Single Sign-On 7.6.13 | — |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 7 | — |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 8 | — |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 9 | — |
| Red Hat | RHEL-8 based Middleware Containers | — |
References
- https://access.redhat.com/errata/RHSA-2026:3947Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:3948Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:76128
- https://access.redhat.com/errata/RHSA-2026:76129
- https://access.redhat.com/errata/RHSA-2026:76130
- https://access.redhat.com/errata/RHSA-2026:76132
- https://access.redhat.com/errata/RHSA-2026:76134
- https://access.redhat.com/security/cve/CVE-2026-2575Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2440149Issue Tracking, Vendor Advisory
Timeline
- Published
- Mar 18, 2026
- Last modified
- Oct 6, 2026
- NVD status
- Modified