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.
Problem types
Allocation of Resources Without Limits or Throttling
Product status
Timeline
| 2026-03-05: | Reported to Red Hat. |
| 2026-05-20: | Made public. |
Credits
Red Hat would like to thank Oleh Konko (1seal.org) for reporting this issue.
References
access.redhat.com/security/cve/CVE-2026-9064
bugzilla.redhat.com/show_bug.cgi?id=2480093 (RHBZ#2480093)