---
id: "CVE-2026-111065"
kind: "vulnerability"
aliases: ["CVE-2026-111065", "GHSA-6cjc-53gc-5rqm"]
title: "AIOHTTP: Connector pool exhaustion via Max-Age overflow"
severity: "medium"
cvss: 6.9
epss: 0.003650000086054206
exploited: false
status: "open"
category: "package"
products: [{"name": "aiohttp", "fixed": ["3.14.4"], "affected": "<= 3.14.3", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["aiohttp", "cwe-770", "package", "python", "web-services"]
not_affected_if: ["aiohttp-version-3.14.4-or-later"]
published_at: "2026-10-19T17:17:03+00:00"
first_seen_at: "2026-10-23T19:11:32+00:00"
updated_at: "2026-10-23T21:57:18+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-6cjc-53gc-5rqm", "first_seen_at": "2026-10-23T19:11:32+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111065", "first_seen_at": "2026-10-23T21:57:18+00:00"}]
---

# AIOHTTP: Connector pool exhaustion via Max-Age overflow

aiohttp, a Python async HTTP client and server library, has an overflow in its Max-Age cookie handling that can cause a connection to be left unclosed. An attacker can exhaust the connection pool until garbage collection frees the connections, which causes a temporary denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- pypi:aiohttp affected <= 3.14.3 fixed 3.14.4

## How to check

pip show aiohttp (or check the lockfile) and compare the installed version against 3.14.4

## Fix

Upgrade aiohttp to 3.14.4 or later.

## Timeline

- 2026-10-23T19:11:32+00:00 ghsa https://github.com/advisories/GHSA-6cjc-53gc-5rqm
- 2026-10-23T21:57:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-111065

## From the sources

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Max-Age processing can overflow and skip closing a connection. An attacker can consequently exhaust the connection pool temporarily until garbage collection resolves the connections. This issue is fixed in version 3.14.4.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_