# CVE-2026-111065: aiohttp cookie Max-Age integer overflow causes connection pool exhaustion

Source: https://junglewise.ai/threats/cve-2026-111065-aiohttp-is-an-asynchronous-http-client-server-framework-for  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-19. Updated: 2026-10-19  
License: CC BY 4.0 with a link back

CVE-2026-111065 · Severity: medium · CVSS 4 · Published 2026-10-19

aiohttp is a Python framework for building asynchronous web applications and HTTP clients. A flaw in cookie Max-Age processing can cause integer overflow, leaving connections open and exhausting the connection pool until garbage collection runs. An attacker can temporarily deny service by rapidly triggering this condition.

Technologies: [Aio-Libs Aiohttp](https://junglewise.ai/threats/technologies/aio-libs-aiohttp), [aiohttp (PyPI)](https://junglewise.ai/threats/technologies/aiohttp). Vendors: [Aio-Libs](https://junglewise.ai/threats/vendors/aio-libs), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-111065 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111065 being exploited in the wild.

**How severe is CVE-2026-111065?** Medium severity, with a CVSS score of 4, published 19 October 2026.

**Which products and versions are affected?** Aio-Libs Aiohttp before 3.14.4; aiohttp (PyPI) <= 3.14.3, ECOSYSTEM:introduced=0,fixed=3.14.4.

**Is there a fix for CVE-2026-111065?** Yes. aiohttp (PyPI): upgrade to 3.14.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-111065 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-111065?** Check whether you run Aio-Libs Aiohttp or aiohttp (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- aiohttp (PyPI): upgrade to 3.14.4 or later

  ```sh
  pip install "aiohttp>=3.14.4"
  ```


## Technical details

An integer overflow in the Max-Age cookie attribute parser causes improper connection lifecycle management, leaving sockets open rather than closing them. The vulnerability is reachable via HTTP responses with malformed Max-Age values and results in temporary connection pool exhaustion; affected connections are eventually reclaimed by garbage collection. The issue is fixed in version 3.14.4.

## Affected products

- aio-libs aiohttp before 3.14.4

## Identifiers

- CVE-2026-111065
- GHSA-6cjc-53gc-5rqm

## Timeline

- 2026-10-19: disclosed

## References

- [https://github.com/aio-libs/aiohttp/commit/9dd8eaf4e31f1237ef2c1574a8c82a739fca5805](https://github.com/aio-libs/aiohttp/commit/9dd8eaf4e31f1237ef2c1574a8c82a739fca5805)
- [https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4](https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4)

## Related threats

- [AIOHTTP WebSocket memory exhaustion via fragmented frames](https://junglewise.ai/threats/cve-2026-123817-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp HTTP request smuggling in pure Python parser](https://junglewise.ai/threats/cve-2026-111750-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp host-only cookie scope bypass in subdomain handling](https://junglewise.ai/threats/cve-2026-111749-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [aiohttp Request scheme manipulation in absolute-form requests](https://junglewise.ai/threats/cve-2026-111748-aiohttp-is-an-asynchronous-http-client-server-framework-for)
- [AIOHTTP multipart request file descriptor exhaustion](https://junglewise.ai/threats/cve-2026-111066-aiohttp-is-an-asynchronous-http-client-server-framework-for)