CVE-2026-9064

389-ds-base: 389-ds-base: unbounded ldap controls count in get_ldapmessage_controls_ext() causes cpu and heap amplification (remote dos)

HIGH
7.5
CVSS Score
Published: May 20, 2026 at 09:00 AM UTC
Updated: August 21, 2026 at 12:16 PM UTC
4 products affected across 3 vendorsEnterprise Linux389 Directory ServerDirectory Server

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Severity
HIGH7.5
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 1781714123 (unaffected)
Vendor states this is fixed in 8060020260609102432.0ca98e7e (unaffected)
Vendor states this is fixed in 8080020260610130252.f969626e (unaffected)
Vendor states this is fixed in 8100020260601104139.37ed7c03 (unaffected)
Vendor states this is fixed in 9020020260615123354.1674d574 (unaffected)
Vendor states this is fixed in 9040020260611130021.1674d574 (unaffected)
Vendor states this is fixed in 0:1.3.11.1-12.el7_9 (unaffected)
Vendor states this is fixed in 0:2.2.4-18.el9_2 (unaffected)
Vendor states this is fixed in 0:2.4.5-25.el9_4 (unaffected)
Vendor states this is fixed in 0:2.6.1-21.el9_6 (unaffected)
Vendor states this is fixed in 0:2.8.0-7.el9_8 (unaffected)
Vendor states this is fixed in 0:3.0.6-18.el10_0 (unaffected)
Vendor states this is fixed in 0:3.2.0-7.el10_2 (unaffected)
Vendor states this is fixed in 8040020260609102422.96015a92 (unaffected)
Vendor states this is fixed in 8060020260609102416.824efc52 (unaffected)
Vendor states this is fixed in 8080020260610125847.6dbb3803 (unaffected)
Vendor states this is fixed in 8100020260601102239.25e700aa (unaffected)
Vendor states this is fixed in 6 (unknown)

References (20)

VDB Entryx_refsource_REDHATMitigationVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-9064
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2480093
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26458
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26452
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26456
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26457
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26459
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:26460

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-770

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