A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function in the LDAP server does not enforce an upper bound on the number of controls per LDAP message. A remote, unauthenticated attacker can send a specially crafted LDAP request containing hundreds of thousands of minimal controls within the default maximum BER message size (2 MB), causing excessive CPU consumption and heap allocation on the server. Under concurrent exploitation, this leads to significant latency degradation, worker thread starvation, or out-of-memory termination, resulting in a denial of service.
History

Wed, 20 May 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 20 May 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Wed, 20 May 2026 10:00:00 +0000

Type Values Removed Values Added
Description A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function in the LDAP server does not enforce an upper bound on the number of controls per LDAP message. A remote, unauthenticated attacker can send a specially crafted LDAP request containing hundreds of thousands of minimal controls within the default maximum BER message size (2 MB), causing excessive CPU consumption and heap allocation on the server. Under concurrent exploitation, this leads to significant latency degradation, worker thread starvation, or out-of-memory termination, resulting in a denial of service.
Title 389-ds-base: 389-ds-base: unbounded ldap controls count in get_ldapmessage_controls_ext() causes cpu and heap amplification (remote dos)
First Time appeared Redhat
Redhat directory Server
Redhat enterprise Linux
Weaknesses CWE-770
CPEs cpe:/a:redhat:directory_server:11
cpe:/a:redhat:directory_server:12
cpe:/a:redhat:directory_server:13
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat directory Server
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published: 2026-05-20T09:00:42.557Z

Updated: 2026-05-20T13:41:09.059Z

Reserved: 2026-05-20T08:19:21.037Z

Link: CVE-2026-9064

cve-icon Vulnrichment

Updated: 2026-05-20T13:40:44.035Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-20T10:16:28.940

Modified: 2026-05-20T14:02:12.280

Link: CVE-2026-9064

cve-icon Redhat

Severity : Important

Publid Date: 2026-05-20T07:30:00Z

Links: CVE-2026-9064 - Bugzilla