HTTP Request Smuggling Affecting netty package, versions <1:4.1.33-2


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
8.42% (95th percentile)

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  • Snyk IDSNYK-ECHOLATEST-NETTY-18016367
  • published19 Jul 2026
  • disclosed26 Sept 2019

Introduced: 26 Sep 2019

CVE-2019-16869  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade Echo:latest netty to version 1:4.1.33-2 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 Echo. See How to fix? for Echo:latest relevant fixed versions and status.

Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked" line), which leads to HTTP request smuggling.

References

CVSS Base Scores

version 3.1