CVE-2026-11884 389-ds-base: 389-ds-base: heap buffer overflow in schema objectclass serialization due to missing oc_superior in size calculation

Description

A heap buffer overflow flaw was found in 389 Directory Server. When serializing objectclass definitions, the oc_superior (SUP) field length is omitted from buffer size calculations in read_schema_dse() and schema_oc_to_string(), but the field is still written via strcat(). An attacker with Directory Manager privileges, or a compromised replication supplier, can trigger a server crash by creating objectclasses with long SUP values. This is an incomplete fix variant of CVE-2025-14905.

Exploitable remotely over the network, with an administrator account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Network

Attack complexity

Low

Privileges required

High

Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Affected products and versions