Resource exhaustion in Red Hat Directory Server 11

CVE-2026-9064

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.

EPSS: 0.008 (54.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-9064?
CVE-2026-9064 is a high-severity vulnerability in Red Hat Directory Server 11, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-05-20.
How severe is CVE-2026-9064?
High severity. CVSS v3 base score is 7.5 out of 10.