What is CVE-2026-54279?

CVE-2026-54279 is a high-severity vulnerability in Aiohttp, classified under Improper Initialization. CVSS score: 7.5/10. Published 2026-06-22.

How severe is CVE-2026-54279?

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

Vulnerability in Aiohttp

CVE-2026-54279

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, host-only cookies that are saved with CookieJar.save() and then restored later with CookieJar.load() lose their host-only status. This vulnerability is fixed in 3.14.1.

Vulnerability class: Dirty Pipe (CVE-2022-0847)

Published 2026-06-22 · last modified 2026-06-26.

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 (39.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.9% 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-665 — Improper Initialization

References

github.com/aio-libs/aiohttp/security/advisories/GHSA-2fqr-mr3j-6wp8 (Third Party Advisory)
github.com/aio-libs/aiohttp/commit/a329a7aacad5284f087af36103aff778746da0f2 (Patch)

Frequently asked questions

What is CVE-2026-54279?: CVE-2026-54279 is a high-severity vulnerability in Aiohttp, classified under Improper Initialization. CVSS score: 7.5/10. Published 2026-06-22.
How severe is CVE-2026-54279?: High severity. CVSS v3 base score is 7.5 out of 10.