# CVE-2026-59881: python-aiohttp: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python

CVE-2026-59881 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-59881, released July 30, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-59881
- Priority: Routine
- CVSS: 5.3 (IMPORTANT)
- EPSS: 0.0052
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 30, 2026

## Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-aiohttp Debian 12.15 (bookworm) | 3.8.4-1+deb12u2 | [DEBIAN-CVE-2026-59881](https://patchblox.com/security/data/fix/linux/debian-cve-2026-59881.md) | Jul 30, 2026 |
| Linux | python-aiohttp Debian 14 | 3.14.3-1 | [DEBIAN-CVE-2026-59881](https://patchblox.com/security/data/fix/linux/debian-cve-2026-59881.md) | Jul 30, 2026 |
| Linux | python-aiohttp opensuse-leap 16.0 | 3.11.16-160000.7.1 | [OPENSUSE-SU-2026:21687-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21687-1.md) | Aug 30, 2026 |
| Linux | python-aiohttp sles 15.6 | 3.6.0-150100.3.41.1 | [SUSE-SU-2026:4113-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4113-1.md) | Sep 9, 2026 |
| Linux | python-aiohttp sles 15.7 | 3.6.0-150100.3.41.1 | [SUSE-SU-2026:4113-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4113-1.md) | Sep 9, 2026 |
| Linux | python-aiohttp sles 16.0 | 3.11.16-160000.7.1 | [SUSE-SU-2026:23571-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23571-1.md) | Aug 30, 2026 |
| Linux | python39-oci-sdk ol 9 | 0:2.187.0-1.0.5.el9 | [ELSA-2026-604898](https://patchblox.com/security/data/fix/linux/elsa-2026-604898.md) | Nov 7, 2026 |
| Linux | python39-oci-sdk-docs ol 9 | 0:2.187.0-1.0.5.el9 | [ELSA-2026-604898](https://patchblox.com/security/data/fix/linux/elsa-2026-604898.md) | Nov 7, 2026 |

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Data as of 2026-11-10T07:50:38Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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