CVE-2026-50269: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python

Q: How do I fix CVE-2026-50269?

aiohttp: upgrade to 3.14.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-50269 being exploited?

CVE-2026-50269 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-2026-50269 affect?

CVE-2026-50269 affects aiohttp. Severity is high (CVSS 7.5). AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. In t

Q: How urgent is CVE-2026-50269?

Priority 42/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-50269 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 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. In the unlikely situation that an application is passing user-controlled strings into MultipartWriter.append(headers=...) or Payload.headers, then an attacker may be able to modify the request to inject headers or

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 55%)
CISA exploited list	No
Weakness	CWE-93, CWE-113
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: < 3.14.0

Fixed in: 3.14.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.14.0 (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-2026-50269?

aiohttp: upgrade to 3.14.0. Exact commands for each OS are on this page.

Is CVE-2026-50269 being exploited?

CVE-2026-50269 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-2026-50269 affect?

CVE-2026-50269 affects aiohttp. Severity is high (CVSS 7.5). AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. In t

How urgent is CVE-2026-50269?

Priority 42/100. High severity; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

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References

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