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)

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.

Published: 2026-05-20 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-9064 is rated Low Risk (38.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-9064

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-20 — 0.08% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9064

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-9064

GitHub Security Advisory for CVE-2026-9064

GHSA-7r3c-wfgh-x96c · Severity: high — A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function in the LDAP server...

OS Trackers for CVE-2026-9064

vendor priority summary link
debian not yet assigned CVE-2026-9064 not yet assigned priority: Debian including 1 source packages (389-ds-base), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): open 4. https://security-tracker.debian.org/tracker/CVE-2026-9064
redhat high — https://access.redhat.com/security/cve/CVE-2026-9064
suse high — https://www.suse.com/security/cve/CVE-2026-9064/
ubuntu medium CVE-2026-9064 medium priority: Ubuntu including 1 source packages (389-ds-base), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, resolute, upstream): needs-triage 7. https://ubuntu.com/security/CVE-2026-9064

Affected software / configurations for CVE-2026-9064

Vendor Product Version Raw CPE
redhat directory_server 11.0 cpe:2.3:a:redhat:directory_server:11.0:*:*:*:*:*:*:*
redhat directory_server 12.0 cpe:2.3:a:redhat:directory_server:12.0:*:*:*:*:*:*:*
redhat directory_server 13.0 cpe:2.3:a:redhat:directory_server:13.0:*:*:*:*:*:*:*
redhat 389_directory_server — cpe:2.3:o:redhat:389_directory_server:-:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux 10.0 cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*

References for CVE-2026-9064

URL Tags
https://access.redhat.com/security/cve/CVE-2026-9064 Mitigation Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2480093 Issue Tracking Vendor Advisory
cvelogic Threat Intelligence