aiohttp vulnerability

What happened

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. In versions 3.13.2 and below, reading multiple invalid cookies can lead to a logging storm. If the cookies attribute is accessed in an application, then an attacker may be able to trigger a storm of warning-level logs using a specially crafted Cookie header. This issue is fixed in 3.13.3.

Affected versions

aiohttp: < 3.13.3 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.