Cyber Resilience

CVE-2025-53643

Low

Published: 14 July 2025

Published
14 July 2025
Modified
14 August 2025
KEV Added
—
Patch
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CVSS Score v4 1.7 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0042 62.6th percentile
Risk Priority 4 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-53643 is a low-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Aiohttp Aiohttp. Its CVSS base score is 1.7 (Low).

Operationally, ranked in the top 37.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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.

CWE(s)
CWE-444

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

aiohttp
aiohttp
≤ 3.12.14

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References