Buffer overflow in Red Hat Directory Server 11

CVE-2026-11884

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (26.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-11884: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-11884?
CVE-2026-11884 is a medium-severity vulnerability in Red Hat Directory Server 11, classified under Heap-based Buffer Overflow. CVSS score: 6.5/10. Published 2026-06-10.
How severe is CVE-2026-11884?
Medium severity. CVSS v3 base score is 6.5 out of 10.