Resource exhaustion in Aio-libs Aiohttp

CVE-2026-22815

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.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (5.6th percentile) — read the EPSS interpretation.

Affected products

Aio-libs Aiohttp — versions < 3.13.4

Weakness classification (CWE)

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-w2fm-2cpv-w7v5 (x_refsource_CONFIRM)
https://github.com/aio-libs/aiohttp/commit/0c2e9da51126238a421568eb7c5b53e5b5d17b36 (x_refsource_MISC)
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 (x_refsource_MISC)