CVE-2025-69229

AIOHTTP vulnerable to DoS through chunked messages

Published Jan 5, 2026 CVSS 4.0 · 6.6 Medium EPSS < 1% KEV · Not listed
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. In versions 3.13.2 and below, handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. If an application makes use of the request.read() method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time. This issue is fixed in version 3.13.3.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4613-1 python-aiohttp security update
Debian DLA Debian DLA DLA-4876-1 python-aiohttp security update
Debian DSA Debian DSA DSA-6141-1 python-aiohttp security update
Github GHSA Github GHSA GHSA-g84x-mcqj-x9qq AIOHTTP vulnerable to DoS through chunked messages
Ubuntu USN Ubuntu USN USN-8032-1 AIOHTTP vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Type Values Removed Values Added
CPEs cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Aio-libs
Aio-libs aiohttp Session
Aio-libs Project
Aio-libs Project aiohttp
Aiohttp
Aiohttp aio-libs
Aiohttp aiohttp
Vendors & Products Aio-libs
Aio-libs aiohttp Session
Aio-libs Project
Aio-libs Project aiohttp
Aiohttp
Aiohttp aio-libs
Aiohttp aiohttp
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Description AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. In versions 3.13.2 and below, handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. If an application makes use of the request.read() method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time. This issue is fixed in version 3.13.3.
Title AIOHTTP vulnerable to DoS through chunked messages
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 6.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jan 6, 2026, 7:02 PM
Reserved
Dec 29, 2025, 8:53 PM
Status
Analyzed
Published
Jan 6, 2026, 12:15 AM
Modified
Oct 11, 2026, 8:10 PM
Severity
Moderate
Public date
Jan 5, 2026, 11:37 PM