SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-9064

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.

HIGH 7.5EPSS 0.81%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.81%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public 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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.81% probability · 55th percentile
CISA KEV
Not listed
Weakness
CWE-770
Affected
redhat/directory server · redhat/389 directory server · redhat/enterprise linux
Source
secalert@redhat.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.