CVE-2026-11884: Red Hat Directory Server 11

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Red Hat Red Hat Directory Server 11
• Red Hat Red Hat Directory Server 12
• Red Hat Red Hat Directory Server 13
• Red Hat Red Hat Enterprise Linux 10
• Red Hat Red Hat Enterprise Linux 6
• Red Hat Red Hat Enterprise Linux 7
• Red Hat Red Hat Enterprise Linux 8
• Red Hat Red Hat Enterprise Linux 9

Published 2026-06-10. Last modified 2026-06-30.