●Change8

Migrating to aiohttp v3.13.3

Version v3.13.3 introduces 1 breaking change. This guide details how to update your code.

Released: 1/3/2026

1
Breaking Changes
1
Migration Steps
2
Affected Symbols

⚠️ Check Your Code

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

Brotlibrotlicffi

Breaking Changes

●Issue #1

Brotli and brotlicffi minimum version is now 1.2. Decompression now has a default maximum output size of 32MiB per decompress call.

Migration Steps

  1. 1
    Ensure Brotli and brotlicffi are at version 1.2 or higher.

Release Summary

This release addresses several vulnerabilities and includes bug fixes for proxy authorization, multipart reading, and websocket frames. It also updates Brotli and brotlicffi dependencies and optimizes web server performance.

Need More Details?

View the full release notes and all changes for aiohttp v3.13.3.

View Full Changelog