What is CVE-2026-54280?

CVE-2026-54280 is a high-severity vulnerability in Aiohttp, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2026-06-22.

How severe is CVE-2026-54280?

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

Vulnerability in Aiohttp

CVE-2026-54280

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, payload resources are not closed correctly when a client disconnects in the middle of a write. If a payload is using an open file or similar limited resource, then an attacker may be able to cause resource starvation temporarily until garbage collection or similar closes the file. This vulnerability is fixed in 3.14.1.

Published 2026-06-22 · last modified 2026-09-16.

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: 0.005 (37.5th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Aiohttp
Aio-Libs Aiohttp — versions < 3.14.1

Weakness classification (CWE)

CWE-404 — Improper Resource Shutdown or Release

References

github.com/aio-libs/aiohttp/security/advisories/GHSA-9x8q-7h8h-wcw9 (Third Party Advisory)
github.com/aio-libs/aiohttp/commit/a762eda5242f6490d6ba667533193f8b473ad587 (Patch)

Frequently asked questions

What is CVE-2026-54280?: CVE-2026-54280 is a high-severity vulnerability in Aiohttp, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2026-06-22.
How severe is CVE-2026-54280?: High severity. CVSS v3 base score is 7.5 out of 10.