CVE-2026-54280: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-54280 is a high-severity flaw (CVSS 7.5) affecting aiohttp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-404
Published	2026-06-22
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: aiohttp

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-22 18:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

aiohttp aiohttp UPGRADE

Affected: >= 3.12.1 and < 3.14.1

Fixed in: 3.14.1

Safe to downgrade to: a release before 3.12.1

1. Check installed version

apt-cache policy aiohttp || rpm -q aiohttp || aiohttp --version

2. UPGRADE to 3.14.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade aiohttp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade aiohttp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.12.1 (Debian / Ubuntu)

apt-cache madison aiohttp sudo apt install aiohttp=<VERSION_BEFORE_3.12.1> sudo apt-mark hold aiohttp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list aiohttp sudo dnf downgrade aiohttp-<VERSION_BEFORE_3.12.1> sudo dnf versionlock add aiohttp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54280?

aiohttp: upgrade to 3.14.1. Exact commands for each OS are on this page.

Is CVE-2026-54280 being exploited?

CVE-2026-54280 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54280 affect?

CVE-2026-54280 affects aiohttp. Severity is high (CVSS 7.5). 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 li

How urgent is CVE-2026-54280?

Priority 41/100. High severity; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

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References

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