HTTP Request Smuggling Affecting netty package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.23% (14th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-NETTY-17328733
  • published13 Jun 2026
  • disclosed12 Jun 2026

Introduced: 12 Jun 2026

NewCVE-2026-50020  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

There is no fixed version for Debian:unstable netty.

NVD Description

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

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, before reading the first request-line, HttpObjectDecoder skips every byte for which Character.isISOControl(b) is true (0x00–0x1F and 0x7F) as well as all whitespace. RFC 9112 §2.2 only asks servers to ignore empty CRLF lines preceding the request-line — a carefully scoped robustness allowance intended to handle HTTP/1.0 POST workarounds. Silently absorbing NUL bytes, SOH, STX, and other non-CRLF control characters goes significantly beyond this, and can be exploited for request-boundary confusion in pipelined or multiplexed transports where a front-end component treats those bytes differently. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

CVSS Base Scores

version 3.1