---
id: CVE-2025-40778
title: >-
  Under certain circumstances, BIND is too lenient when accepting records from
  answers, allowing an attacker to inject forged data into the cache.

  This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through
  9.18.39, 9.20.0 th…
summary: >-
  Under certain circumstances, BIND is too lenient when accepting records from
  answers, allowing an attacker to inject forged data into the cache.

  This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through
  9.18.39, 9.20.0 th…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N'
cwe:
  - CWE-349
published: '2025-10-22'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T11:10:00.250'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40778'
references:
  - url: 'https://kb.isc.org/docs/cve-2025-40778'
    label: security-officer@isc.org
  - url: 'http://www.openwall.com/lists/oss-security/2025/10/22/1'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://gist.github.com/N3mes1s/f76b4a606308937b0806a5256bc1f918'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.00667
epssPercentile: 0.50326
exploits:
  github: 3
  githubRepos:
    - 'https://github.com/nehkark/CVE-2025-40778'
    - 'https://github.com/nicholasC03/DNS-Poisoning-Triage-Lab'
    - >-
      https://github.com/sirbuvladste/BIND-9-Cache-Poisoning-PoC---CVE-2025-40778
  checkedAt: '2026-10-08T11:32:03.418Z'
exploitAvailable: true
ingestedAt: '2026-10-08T11:31:27.547Z'
---

## Overview

Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache.
This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.

## Remediation

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