CVE-2025-53643

AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections

Published Jul 14, 2025 CVSS 4.0 · 1.7 Low EPSS < 1% KEV · Not listed
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.12.14, the Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. Version 3.12.14 contains a patch for this issue.

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
EUVD EUVD EUVD-2025-21384 AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
Github GHSA Github GHSA GHSA-9548-qrrj-x5pj AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
History
Type Values Removed Values Added
First Time appeared Aiohttp
Aiohttp aiohttp
CPEs cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*
Vendors & Products Aiohttp
Aiohttp aiohttp
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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:H/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics epss

{'score': 0.00048}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

threat_severity

Low

Type Values Removed Values Added
Description AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.12.14, the Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. Version 3.12.14 contains a patch for this issue.
Title AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
Weaknesses CWE-444
References
Metrics cvssV4_0

{'score': 1.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 15, 2025, 7:50 PM
Reserved
Jul 7, 2025, 2:20 PM
Status
Analyzed
Published
Jul 14, 2025, 9:15 PM
Modified
Jun 17, 2026, 9:38 AM
Severity
Low
Public date
Jul 14, 2025, 8:17 PM