Change8

Migrating to aiohttp v3.14.1

Version v3.14.1 introduces 1 breaking change. This guide details how to update your code.

Released: 6/7/2026

1
Breaking Changes
0
Migration Steps
11
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

aiohttp.TCPConnectoraiohttp.ClientConnectionErroraiohttp.CookieJaraiohttp.CookieJar.saveaiohttp.CookieJar.loadaiohttp.DigestAuthMiddlewareaiohttp.StreamReader.readanyaiohttp.StreamReader.read_nowaitaiohttp.web.Response.write_eofaiohttp.payload.Payloadaiohttp.InvalidUrlClientError

Breaking Changes

Issue #1

aiohttp.TCPConnector now rejects legacy non-canonical numeric IPv4 host forms (e.g., 2130706433, 017700000001, 127.1) with aiohttp.InvalidUrlClientError. Only canonical dotted-quad IPv4 literals are now treated as IP address literals. Hosts that do not conform to this will be sent through the configured resolver. To fix, ensure all IPv4 host literals are in the standard dotted-quad format (e.g., 127.0.0.1).

Release Summary

This release addresses several bugs in aiohttp, including race conditions, connection handling, parser enforcement, and cookie management. It also improves security by scoping digest authentication and rejecting non-canonical IPv4 host forms.

Need More Details?

View the full release notes and all changes for aiohttp v3.14.1.

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