Sourced from aiohttp's releases.

3.12.14

Bug fixes

• Fixed file uploads failing with HTTP 422 errors when encountering 307/308 redirects, and 301/302 redirects for non-POST methods, by preserving the request body when appropriate per :rfc:9110#section-15.4.3-3.1 -- by :user:bdraco.

  Related issues and pull requests on GitHub: #11270.

• Fixed :py:meth:ClientSession.close() <aiohttp.ClientSession.close> hanging indefinitely when using HTTPS requests through HTTP proxies -- by :user:bdraco.

  Related issues and pull requests on GitHub: #11273.

• Bumped minimum version of aiosignal to 1.4+ to resolve typing issues -- by :user:Dreamsorcerer.

  Related issues and pull requests on GitHub: #11280.

Features

• Added initial trailer parsing logic to Python HTTP parser -- by :user:Dreamsorcerer.

  Related issues and pull requests on GitHub: #11269.

Improved documentation

• Clarified exceptions raised by WebSocketResponse.send_frame et al. -- by :user:DoctorJohn.

  Related issues and pull requests on GitHub: #11234.

... (truncated)

Sourced from aiohttp's changelog.

3.12.14 (2025-07-10)

Bug fixes

• Fixed file uploads failing with HTTP 422 errors when encountering 307/308 redirects, and 301/302 redirects for non-POST methods, by preserving the request body when appropriate per :rfc:9110#section-15.4.3-3.1 -- by :user:bdraco.

  Related issues and pull requests on GitHub: :issue:11270.

• Fixed :py:meth:ClientSession.close() <aiohttp.ClientSession.close> hanging indefinitely when using HTTPS requests through HTTP proxies -- by :user:bdraco.

  Related issues and pull requests on GitHub: :issue:11273.

• Bumped minimum version of aiosignal to 1.4+ to resolve typing issues -- by :user:Dreamsorcerer.

  Related issues and pull requests on GitHub: :issue:11280.

Features

• Added initial trailer parsing logic to Python HTTP parser -- by :user:Dreamsorcerer.

  Related issues and pull requests on GitHub: :issue:11269.

Improved documentation

• Clarified exceptions raised by WebSocketResponse.send_frame et al. -- by :user:DoctorJohn.

... (truncated)

• 90b6cf6 Release 3.12.14 (#11298)
• 13b20a1 [PR #11290/16703bb9 backport][3.12] Fix file uploads failing with HTTP 422 on...
• edf2abd [PR #11289/e38220fc backport][3.12] Fix ClientSession.close() hanging with HT...
• e8d774f Add trailer parsing logic (#11269) (#11287)
• 0389371 [PR #11280/91108c90 backport][3.12] Bump the minimum supported version of aio...
• ce3c0a7 Bump aiosignal from 1.3.2 to 1.4.0 (#11267) (#11279)
• 133e254 [PR #11234/a83597fa backport][3.12] Document exceptions raised by send_frame ...
• 4ad78b3 Increment version to 3.12.14.dev0 (#11216)
• See full diff in compare view

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