High severity · published May 20, 2026
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)
7.5
CVSS
0.8%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 57% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Directory Server 11.5 E4S for RHEL 8 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 11.7 E4S for RHEL 8 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 11.9 for RHEL 8 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 12 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 12.2 E4S for RHEL 9 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 12.4 E4S for RHEL 9 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 13 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Directory Server 13.2 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat Enterprise Linux 7 Extended Lifecycle Support · Red Hat
All versions, or not specified · source: vendor, CISA
Affected product
RH
Red Hat Directory Server 11.5 E4S for RHEL 8
Red Hat
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9064
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-9064
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26452
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26453
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26454
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26455
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26456
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26457
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