GitHub Advisoryadvisory · Maven

GHSA-xv6h-r36f-3gp5 Keycloak: Denial of Service due to excessive SAMLRequest decompression

MEDIUM Published 2026-03-18 Modified 2026-10-06 Official page ↗
Aliases
CVE-2026-2575
Ecosystem
Maven
Packages
org.keycloak:keycloak-saml-adapter-core, org.keycloak:keycloak-saml-core, org.keycloak:keycloak-services
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weaknesses
CWE-409
Reviewed
2026-03-18

Affected packages

• Maven org.keycloak:keycloak-saml-adapter-core: < 26.5.4 → fixed in 26.5.4 • Maven org.keycloak:keycloak-saml-core: < 26.5.4 → fixed in 26.5.4 • Maven org.keycloak:keycloak-services: < 26.5.4 → fixed in 26.5.4

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.

Related

Alias · CVE (1)

Weakness · CWE (1)

  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification) weakness

References