HTTP Request Smuggling Affecting netty package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.29% (22nd percentile)

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  • Snyk IDSNYK-ECHOLATEST-NETTY-18426990
  • published30 Jul 2026
  • disclosed29 Jul 2026

Introduced: 29 Jul 2026

NewCVE-2026-59900  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest netty.

NVD Description

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

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (Http2StreamFrameToHttpObjectCodec and InboundHttp2ToHttpAdapter) fails to deduplicate or validate Host headers when an HTTP/2 client supplies both the :authority pseudo-header and a literal host header in a single HEADERS frame. The translator maps :authority to Host and separately copies the literal host header, producing an HttpRequest object containing two Host headers with attacker-controlled differing values. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS Base Scores

version 3.1