PYSEC-2026-2101

At a glance

Published: 2026-04-01 21:17 UTC
Updated: 2026-07-13 07:15 UTC
CVE: CVE-2026-34519
Aliases: GHSA-mwh4-6h8g-pg8w
CVSS_V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.

Affected packages

Package	Versions
PyPI · aiohttp	introduced 0, fixed 3.13.4

References

https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 ADVISORY
https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b FIX
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mwh4-6h8g-pg8w FIX

Sources

Source	Licence
OSV.dev	CC-BY 4.0 — PyPA Advisory Database