Denial of Service Vulnerability in 389-ds-base LDAP Server by Red Hat
CVE-2026-9064

7.5HIGH

Key Information:

Vendor: Red Hat
Status: Red Hat Directory Server 11.5 E4s For Rhel 8; Red Hat Directory Server 11.7 E4s For Rhel 8; Red Hat Directory Server 11.9 For Rhel 8; Red Hat Directory Server 12.2 E4s For Rhel 9
Vendor: CVE Published:; 20 May 2026

What is CVE-2026-9064?

A flaw exists in the 389-ds-base LDAP server with the get_ldapmessage_controls_ext() function that allows a remote, unauthenticated attacker to exploit the server. By sending a crafted LDAP request containing excessive controls, an attacker can consume significant CPU resources and trigger heap allocation issues. This exploitation could lead to severe latency, worker thread starvation, or out-of-memory conditions, ultimately resulting in a denial of service that impacts the availability and performance of the LDAP server.