CVE-2026-54280 AIOHTTP: Payload Response Resources Are Not Closed After Mid-Body Disconnect

Low 1.7 Published Updated

Attackers can cause resource starvation by triggering mid-body disconnects, preventing proper closure of file resources in the aiohttp library.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-54280?

CVE-2026-54280 is a low-severity denial of service vulnerability in aio-libs aiohttp, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-404

Which versions are affected by CVE-2026-54280?

3 open source packages ship an affected version, including aiohttp. It affects 1 product.

PackageAffectedFixed in
aiohttp PyPIAll versions3.14.1
aiohttp PyPIAll versions3.14.1
aiohttp PyPIAll versions3.14.1

Products include Aiohttp Aiohttp.

How do I fix CVE-2026-54280?

Upgrade aiohttp to 3.14.1 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-54280 being exploited?

There is no known exploitation of CVE-2026-54280 in the wild and no public exploit code.

Sources

Also known as AZL-90662, CLEANSTART-2026-HP74400, CLEANSTART-2026-KI86994, DEBIAN-CVE-2026-54280, ECHO-d1ac-9337-96ab, GHSA-9x8q-7h8h-wcw9 and 20 more.

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