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
- Red Hat Directory Server 11
- Red Hat Directory Server 11.5 E4s For Rhel 8 — versions 8060020260609102432.0ca98e7e
- Red Hat Directory Server 11.7 E4s For Rhel 8 — versions 8080020260610130252.f969626e
- Red Hat Directory Server 11.9 For Rhel 8 — versions 8100020260601104139.37ed7c03
- Red Hat Directory Server 12
- Red Hat Directory Server 12.2 E4s For Rhel 9 — versions 9020020260615123354.1674d574
- Red Hat Directory Server 12.4 E4s For Rhel 9 — versions 9040020260611130021.1674d574
- Red Hat Directory Server 13
- Red Hat Directory Server 13.2 — versions 1781714123
- Red Hat Enterprise Linux 10 — versions 0:3.2.0-7.el10_2
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, Mitigation, vdb-entry, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking, Issue Tracking, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
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.