What’s Vulnerable › Vulnerabilities

CVE-2026-111064: aiohttp server lacks an initial request/header timeout

• Severity: high (CVSS 8.2 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-19 · updated 2026-10-28
• Weakness: CWE-770

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, keepalive timeout handling is absent during the initial portion of a request. An attacker can keep an idle connection open indefinitely before sending any request data, consuming server connection capacity. This issue is fixed in version 3.14.4.

Affected products

• Pypi Aiohttp: before 3.14.4; 0.1, 0.10.0, 0.10.1, 0.10.2, 0.11.0, 0.12.0 (+304) — fixed in 3.14.4
• aio-libs aiohttp: before 3.14.4

How to fix

Upgrade to a fixed version: Pypi Aiohttp 3.14.4. Check the vendor advisory for mitigations.

References

• https://github.com/aio-libs/aiohttp/commit/be846822b4b3a5a54b6163e794b42dc06fba54a3
• https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-5wr8-gcqf-gqf3

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