HTTP Request Smuggling Affecting netty package, versions <1:4.1.45-1ubuntu0.1~esm6


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.25% (16th percentile)

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  • Snyk IDSNYK-UBUNTU2004-NETTY-16781701
  • published3 Jun 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

CVE-2026-42585  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 netty to version 1:4.1.45-1ubuntu0.1~esm6 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream netty package and not the netty package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS Base Scores

version 3.1