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HTTP Request Smuggling The advisory has been revoked - it doesn't affect any version of package python-waitress.src  (opens in a new tab)

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EPSS
0.9% (76th percentile)

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  • Snyk IDSNYK-RHEL10-PYTHONWAITRESSSRC-15325079
  • published21 Feb 2026
  • disclosed20 Dec 2019
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Introduced: 20 Dec 2019

CVE-2019-16786  (opens in a new tab)
CWE-444  (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-waitress.src package and not the python-waitress.src package as distributed by RHEL.

Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: "Transfer-Encoding: gzip, chunked" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.

References