CVE-2026-54275: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python

Q: How do I fix CVE-2026-54275?

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

Q: Is CVE-2026-54275 being exploited?

CVE-2026-54275 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-54275 affect?

CVE-2026-54275 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, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same

Q: How urgent is CVE-2026-54275?

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

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-54275 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, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check. This vulnerab

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-297
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: < 3.14.1

Fixed in: 3.14.1

Safe to downgrade to: no unaffected older release

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.

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-2026-54275?

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

Is CVE-2026-54275 being exploited?

CVE-2026-54275 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-2026-54275 affect?

CVE-2026-54275 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, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same

How urgent is CVE-2026-54275?

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

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-34515 HIGH 7.5 UPGRADE AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python
CVE-2026-34516 HIGH 7.5 UPGRADE AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python
CVE-2026-54274 HIGH 7.5 UPGRADE AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python
CVE-2026-54277 HIGH 7.5 UPGRADE AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python
CVE-2026-50269 HIGH 7.5 UPGRADE AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python

References

← Back to latest CVEs