CVE-2026-34525: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This…

medium6.3CVSS 4.0

AVNACHATPPRNUINVCNVILVANSCLSILSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
aio-libs	aiohttp	< 3.13.4	3.13.4
aiohttp	aiohttp	>= 0 < 3.13.4	3.13.4
debian	python-aiohttp	—	—

CVSS provenance

nvdv4.06.3MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

osv6.3MEDIUM