# CVE-2026-111066: AIOHTTP multipart request file descriptor exhaustion

Source: https://junglewise.ai/threats/cve-2026-111066-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-2026-111066 · Severity: high · CVSS 4 · Published 2026-10-19

AIOHTTP is a Python HTTP client/server framework. An unauthenticated attacker can send specially crafted multipart requests to exhaust file descriptors on the server, potentially causing service degradation or denial of service. This occurs when the application uses Request.post() to handle multipart data.

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-2026-111066 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111066 being exploited in the wild.

**How severe is CVE-2026-111066?** High severity, with a CVSS score of 4, published 19 October 2026.

**Which products and versions are affected?** Aio-Libs Aiohttp 2.0.0 through 3.14.3; aiohttp (PyPI) >= 2.0.0, < 3.14.4, ECOSYSTEM:introduced=2.0.0,fixed=3.14.4.

**Is there a fix for CVE-2026-111066?** 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-2026-111066 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-111066?** 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

The vulnerability exists in multipart request processing in AIOHTTP versions 2.0.0 through 3.14.3, where handlers using Request.post() fail to properly manage file descriptors, leaving an unbounded number open. An unauthenticated attacker can craft multipart requests that trigger this leak, exhausting system resources. The fix switches multipart handling to use spooled temporary files to bound file descriptor usage.

## Affected products

- aio-libs AIOHTTP 2.0.0 through 3.14.3

## Identifiers

- CVE-2026-111066
- GHSA-9xw5-w5jj-pvcg

## Timeline

- 2026-10-19: disclosed
- 2026-10-05: patched

## References

- [https://github.com/aio-libs/aiohttp/commit/2d94633b7f1b4c1ba07d647b629a8440652b2d09](https://github.com/aio-libs/aiohttp/commit/2d94633b7f1b4c1ba07d647b629a8440652b2d09)
- [https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4](https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4)

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