What is CVE-2026-22815?

CVE-2026-22815 is a high-severity vulnerability in Aiohttp, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-04-01.

How severe is CVE-2026-22815?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in 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)

Published 2026-04-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (35.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Aiohttp
Aio-Libs Aiohttp — versions < 3.13.4

Weakness classification (CWE)

References

github.com/aio-libs/aiohttp/security/advisories/GHSA-w2fm-2cpv-w7v5 (Patch, Vendor Advisory)
github.com/aio-libs/aiohttp/commit/0c2e9da51126238a421568eb7c5b53e5b5d17b36 (Patch)
github.com/aio-libs/aiohttp/releases/tag/v3.13.4 (Release Notes)

Frequently asked questions

What is CVE-2026-22815?: CVE-2026-22815 is a high-severity vulnerability in Aiohttp, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-04-01.
How severe is CVE-2026-22815?: High severity. CVSS v3 base score is 7.5 out of 10.