CVE-2023-47627: Aiohttp

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. The HTTP parser in AIOHTTP has numerous problems with header parsing, which could lead to request smuggling. This parser is only used when AIOHTTP_NO_EXTENSIONS is enabled (or not using a prebuilt wheel). These bugs have been addressed in commit `d5c12ba89` which has been included in release version 3.8.6. Users are advised to upgrade. There are no known workarounds for these issues.

Affected products

• Aiohttp Aiohttp: before 3.8.6 (fixed in 3.8.6)

Published 2023-11-14. Last modified 2026-06-17.