CVE-2026-42304: Twisted DNS DoS Freezes Servers with Chained Pointers
The National Vulnerability Database has detailed CVE-2026-42304, a high-severity Denial of Service (DoS) vulnerability in Twisted, the event-based framework for internet applications. This flaw, present in versions prior to 26.4.0rc2, specifically impacts the twisted.names module, which handles DNS operations.
The vulnerability stems from resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by crafting a TCP DNS packet containing deeply chained compression pointers. This malicious packet bypasses existing loop-prevention logic, forcing the single-threaded Twisted reactor into millions of recursive lookups, effectively freezing the server and causing a complete DoS. The National Vulnerability Database highlights that this is a critical issue for any system relying on Twisted for DNS services.
Defenders must prioritize patching. The National Vulnerability Database confirms that this vulnerability is fixed in Twisted version 26.4.0rc2. Organizations using Twisted in their infrastructure, particularly for DNS resolution or any service that processes DNS packets, need to upgrade immediately to mitigate the risk of unauthenticated remote attackers taking their services offline.
What This Means For You
- If your organization utilizes Twisted, particularly for DNS services, you are exposed to a remote, unauthenticated Denial of Service attack. This isn't theoretical; a single crafted packet can bring down your server. Prioritize upgrading to Twisted version 26.4.0rc2 or later immediately. Verify your Twisted dependencies and deployment.
Related ATT&CK Techniques
🛡️ Detection Rules
2 rules · 6 SIEM formats2 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-42304: Twisted DNS DoS - Chained Pointer Attack
title: CVE-2026-42304: Twisted DNS DoS - Chained Pointer Attack
id: scw-2026-05-13-ai-1
status: experimental
level: critical
description: |
Detects potential exploitation of CVE-2026-42304 by looking for DNS queries to port 53 that contain chained pointers, indicated by repeated dots in the query. This specific pattern is associated with the resource exhaustion DoS attack in Twisted's DNS module.
author: SCW Feed Engine (AI-generated)
date: 2026-05-13
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-42304/
tags:
- attack.denial_of_service
- attack.t1499
logsource:
category: dns
detection:
selection:
dst_port:
- 53
query|contains:
- '..'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-42304 | DoS | Twisted framework versions prior to 26.4.0rc2 |
| CVE-2026-42304 | DoS | twisted.names module |
| CVE-2026-42304 | DoS | DNS name decompression via crafted TCP DNS packet with deeply chained compression pointers |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 14, 2026 at 00:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
Believe this infringes your rights? Submit a takedown request.
Related coverage
OPNsense RCE: Critical Flaw Allows Root Access via DHCP Input
CVE-2026-45158 — OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, unsanitized user input is passed to the DHCP configuration of the...
Hoppscotch CVE-2026-44478: Unauthenticated Infrastructure Secret Leak
CVE-2026-44478 — hoppscotch is an open source API development ecosystem. The fix for CVE-2026-28215 in version 2026.2.0 addresses the unauthenticated POST /v1/onboarding/config endpoint by checking...
CVE-2026-44471: gitoxide Symlink Vulnerability Exposes Filesystem to Attack
CVE-2026-44471 — gitoxide is an implementation of git written in Rust. Prior to 0.21.1, a malicious tree can be constructed that will, when checked out...