Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M

CVE-2026-111064aiohttp server lacks an initial request/header timeout

High 8.2

In plain English

A high-severity resource allocation without limits in aiohttp from aio-libs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.2High

Exploit odds (30 days)0.4%top 65.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, keepalive timeout handling is absent during the initial portion of a request. An attacker can keep an idle connection open indefinitely before sending any request data, consuming server connection capacity. This issue is fixed in version 3.14.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	python-aiohttp	no fix listed	DEBIAN-CVE-2026-111064
Debian:13	python-aiohttp	no fix listed	DEBIAN-CVE-2026-111064
Debian:14	python-aiohttp	no fix listed	DEBIAN-CVE-2026-111064
PyPI	aiohttp	3.14.4	GHSA-5wr8-gcqf-gqf3
Ubuntu:26.10	python-aiohttp	no fix listed	UBUNTU-CVE-2026-111064

Affected products (as reported)

Vendor	Product	Versions
aio-libs	aiohttp	< 3.14.4

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-5wr8-gcqf-gqf3 x_refsource_CONFIRM
https://github.com/aio-libs/aiohttp/commit/be846822b4b3a5a54b6163e794b42dc06fba54a3 x_refsource_MISC
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4 x_refsource_MISC