CVE-2026-22815: AIOHTTP: Uncapped memory usage possible through aiohttp allowing unlimited trailer headers
Summary
Insufficient restrictions in header/trailer handling could cause uncapped memory usage.
Impact
An application could cause memory exhaustion when receiving an attacker controlled request or response. A vulnerable web application could mitigate these risks with a typical reverse proxy configuration.
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Patch: https://github.com/aio-libs/aiohttp/commit/0c2e9da51126238a421568eb7c5b53e5b5d17b36
Other sources
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, insufficient restrictions in header/trailer handling could cause uncapped memory usage. This issue has been patched in version 3.13.4.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pip/aiohttpto a version that resolves this vulnerability.Fixed in 3.13.4 - Upgrade
Upgrade
debian/python-aiohttpto a version that resolves this vulnerability.Fixed in 3.7.4-1+deb11u2Fixed in 3.14.1-4 - Upgrade
Upgrade
aiohttpto a version that resolves this vulnerability.Fixed in 3.13.4Patch 0c2e9da51126238a421568eb7c5b53e5b5d17b36 - Compensating control
Use a typical reverse proxy configuration to mitigate uncapped memory usage via attacker-controlled requests/responses (uncapped trailer headers) when using aiohttp before 3.13.4.