Sourced from waitress's changelog.

2.1.1

Security Bugfix

- Waitress now validates that chunked encoding extensions are valid, and don't
  contain invalid characters that are not allowed. They are still skipped/not
  processed, but if they contain invalid data we no longer continue in and
  return a 400 Bad Request. This stops potential HTTP desync/HTTP request
  smuggling. Thanks to Zhang Zeyu for reporting this issue. See
  https://github.com/Pylons/waitress/security/advisories/GHSA-4f7p-27jc-3c36


Waitress now validates that the chunk length is only valid hex digits when
parsing chunked encoding, and values such as 0x01 and +01 are no
longer supported. This stops potential HTTP desync/HTTP request smuggling.
Thanks to Zhang Zeyu for reporting this issue. See
https://github.com/Pylons/waitress/security/advisories/GHSA-4f7p-27jc-3c36


Waitress now validates that the Content-Length sent by a remote contains only
digits in accordance with RFC7230 and will return a 400 Bad Request when the
Content-Length header contains invalid data, such as +10 which would
previously get parsed as 10 and accepted. This stops potential HTTP
desync/HTTP request smuggling Thanks to Zhang Zeyu for reporting this issue. See
https://github.com/Pylons/waitress/security/advisories/GHSA-4f7p-27jc-3c36


2.1.0
Python Version Support

• Python 3.6 is no longer supported by Waitress

• Python 3.10 is fully supported by Waitress

Bugfix

- ``wsgi.file_wrapper`` now sets the ``seekable``, ``seek``, and ``tell``
  attributes from the underlying file if the underlying file is seekable. This
  allows WSGI middleware to implement things like range requests for example
See Pylons/waitress#359 and
Pylons/waitress#363

In Python 3 OSError is no longer subscriptable, this caused failures on
Windows attempting to loop to find an socket that would work for use in the
trigger.

</tr></table>

... (truncated)

• 9e0b8c8 Merge pull request from GHSA-4f7p-27jc-3c36
• b28c9e8 Prep for 2.1.1
• bd22869 Remove extraneous calls to .strip() in Chunked Encoding
• d9bdfa0 Validate chunk size in Chunked Encoding are HEXDIG
• d032a66 Error when receiving back Chunk Extension
• 884bed1 Update tests to remove invalid chunked encoding chunk-size
• 1f6059f Be more strict in parsing Content-Length
• e75b0d9 Add new regular expressions for Chunked Encoding
• 22c0394 Merge pull request #367 from Pylons/fixup/collect-wasyncore-tests
• dc15d9f Make sure to collect all wasyncore tests
• Additional commits viewable in compare view

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot use this milestone will set the current milestone as the default for future PRs for this repo and language

You can disable automated security fix PRs for this repo from the Security Alerts page.