---
id: CVE-2026-27854
title: >-
  An attacker might be able to trigger a use-after-free by sending crafted DNS
  queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua
  code
summary: >-
  An attacker might be able to trigger a use-after-free by sending crafted DNS
  queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua
  code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the
  DN…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L'
cwe:
  - CWE-416
vendor: powerdns
product: dnsdist
affected:
  - 'dnsdist >= 1.9.0, < 1.9.12'
  - 'dnsdist >= 2.0.0, < 2.0.3'
patched:
  - dnsdist 2.0.3
published: '2026-03-31'
updated: '2026-07-25'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-27854'
references:
  - url: >-
      https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-02.html
    label: security@open-xchange.com
tags:
  - nvd
epss: 0.01338
epssPercentile: 0.70057
ingestedAt: '2026-07-25T11:55:02.653Z'
---

## Overview

An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.

## Affected

- `dnsdist >= 1.9.0, < 1.9.12`
- `dnsdist >= 2.0.0, < 2.0.3`

## Remediation

Upgrade past the affected range:

- `dnsdist 2.0.3`