CVE-2026-42580 — Netty is an asynchronous, event-driven network application

title: CVE-2026-42580 - Netty Chunk Size Integer Overflow Request Smuggling
id: scw-2026-05-13-ai-1
status: experimental
level: critical
description: |
  Detects potential request smuggling attacks exploiting CVE-2026-42580 in Netty. The vulnerability allows an attacker to bypass security controls by manipulating the 'Content-Length' and 'Transfer-Encoding' headers, leading to a chunk size integer overflow. This rule looks for a POST request with a suspicious chunk size indicator ('00000000') in the query string, which is indicative of an attempt to exploit this overflow.
author: SCW Feed Engine (AI-generated)
date: 2026-05-13
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-42580/
tags:
  - attack.initial_access
  - attack.t1190
logsource:
    category: webserver
detection:
  selection:
      cs-uri-query|contains:
          - '00000000'
      cs-method|contains:
          - 'POST'
      condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse