CVE-2025-53643

14.07.2025, 21:15

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.

HTTP Request/Response Smuggling

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub_M	CNA	---				---
CISA-ADP	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 12%

Vendor	Product	Version
aiohttp	aiohttp	𝑥 < 3.12.14

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

python-aiohttp

bullseye	postponed
trixie	no-dsa
bookworm	no-dsa
bullseye (security)	vulnerable
bookworm (security)	vulnerable
forky	vulnerable
sid	vulnerable

Ubuntu Releases

Ubuntu Product

Codename

python-aiohttp

plucky	needs-triage
noble	needs-triage
jammy	needs-triage
focal	needs-triage
bionic	needs-triage
xenial	needs-triage

Common Weakness Enumeration

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

References

https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-9548-qrrj-x5pj