---
id: CVE-2026-11787
title: >-
  389-ds-base: 389-ds-base: heap buffer over-read in ldap_utf8prev() via
  str2simple filter parsing
summary: >-
  A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads
  bytes before the start of a buffer without bounds checking, causing a heap
  buffer over-read in string filter parsing that may influence internal filter
  processi…
severity: medium
cvss: 5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-126
vendor: Red Hat
product: 'redhat-ds:11/389-ds-base'
affected:
  - 'redhat-ds:11/389-ds-base (all versions)'
  - 'redhat-ds:12/389-ds-base (all versions)'
  - 389-ds-base (all versions)
  - 389-ds-base (all versions)
  - 389-ds-base
  - 389-ds-base (all versions)
  - 389-ds-base (all versions)
  - 389-ds-base (all versions)
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-09T13:30:15.301451Z'
published: '2026-06-09'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T16:22:32.393Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-11787'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-11787'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2485425'
    label: RHBZ#2485425
tags:
  - cve.org
epss: 0.00177
epssPercentile: 0.073
ingestedAt: '2026-11-05T22:38:31.342Z'
---

## Overview

A flaw was found in 389 Directory Server. The ldap_utf8prev() function reads bytes before the start of a buffer without bounds checking, causing a heap buffer over-read in string filter parsing that may influence internal filter processing behavior.

## Affected

- `redhat-ds:11/389-ds-base (all versions)`
- `redhat-ds:12/389-ds-base (all versions)`
- `389-ds-base (all versions)`
- `389-ds-base (all versions)`
- `389-ds-base`
- `389-ds-base (all versions)`
- `389-ds-base (all versions)`
- `389-ds-base (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

No direct workaround addresses the code-level bug; network-level mitigations (proxies, WAFs, filter validation) do not apply. Mitigation measures to reduce exposure: restrict plugin configuration access (MEP originFilter, UID uniqueness nsUniqueAttribute, strict ACIs on cn=config); restrict Directory Manager access for ACI, MEP, or uniqueness plugin configuration; harden replication topology to restrict replication peers; monitor for anomalous search result sets that may indicate exploitation.