---
id: CVE-2026-83813
title: >-
  Twisted: DNS Response Spoofing in twisted.names Due to Missing Source Address
  Validation
summary: >-
  Twisted is an event-based framework for internet applications, supporting
  Python 3.6+. Prior to 26.10.0rc1, twisted.names.dns.DNSDatagramProtocol
  accepts a UDP DNS response for a pending query when its 16-bit transaction ID
  matches but d…
severity: low
cvss: 3.1
cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-346
vendor: twisted
product: twisted
affected:
  - twisted < 26.7.0rc1
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T20:21:54.364Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-83813'
references:
  - url: 'https://github.com/twisted/twisted/security/advisories/GHSA-jj36-9pvh-vj5r'
    label: 'https://github.com/twisted/twisted/security/advisories/GHSA-jj36-9pvh-vj5r'
  - url: 'https://github.com/twisted/twisted/pull/12700'
    label: 'https://github.com/twisted/twisted/pull/12700'
  - url: >-
      https://github.com/twisted/twisted/commit/b53e1c3477c209b5609a1c74cf9e48373b5879ac
    label: >-
      https://github.com/twisted/twisted/commit/b53e1c3477c209b5609a1c74cf9e48373b5879ac
  - url: 'https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1'
    label: 'https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1'
tags:
  - cve.org
ingestedAt: '2026-10-23T21:38:13.061Z'
---

## Overview

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.names.dns.DNSDatagramProtocol accepts a UDP DNS response for a pending query when its 16-bit transaction ID matches but does not verify that the response came from the queried host and port. An attacker able to deliver a packet to the resolver's listening port with the correct transaction ID can inject a forged answer. The standard twisted.names.client.Resolver uses a new random source port for each query, increasing off-path attack complexity, while applications that reuse a DNSDatagramProtocol instance expose only the transaction-ID search space after the first query. A successful forgery can redirect hostname resolution and enable mail interception, server-side request forgery, or man-in-the-middle positioning. This issue is fixed in version 26.10.0rc1.

## Affected

- `twisted < 26.7.0rc1`

## Remediation

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