---
id: CVE-2026-11793
title: A stack buffer overflow flaw was found in 389 Directory Server
summary: >-
  A stack buffer overflow flaw was found in 389 Directory Server. The
  checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into
  a 256-byte stack buffer without bounds checking when parsing
  reversible-encrypted attribut…
severity: medium
cvss: 4.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-121
vendor: redhat
product: 389_directory_server
affected:
  - 389_directory_server
published: '2026-06-09'
updated: '2026-08-07'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-11793'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-11793'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2484914'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00282
epssPercentile: 0.18471
ingestedAt: '2026-08-07T07:12:17.324Z'
---

## Overview

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

## Affected

- `389_directory_server`

## Remediation

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