PatchTheCVECVE-2026-59881: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python
40
This month
MEDIUM 6.9REMOTE
CVE-2026-59881 is a medium-severity flaw (CVSS 6.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 56%) |
| CISA exploited list | No |
| Weakness | CWE-20 |
| Published | 2026-07-30 |
| Last modified | 2026-10-23 |
Publisher (CNA): GitHub, Inc.
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.