Vulnerability · Published Jan 5, 2026 · Assigned by GitHub_M

CVE-2025-69224AIOHTTP's Unicode processing of header values could cause parsing discrepancies

Medium 6.3

In plain English

A medium-severity security flaw in aiohttp from aio-libs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.3Medium
Exploit odds (30 days)0.2%top 83.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below of the Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. 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. This issue is fixed in version 3.13.3.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23py3-aiohttp3.13.3-r0ALPINE-CVE-2025-69224
Alpine:v3.24py3-aiohttp3.13.3-r0ALPINE-CVE-2025-69224
Debian:12python-aiohttp3.8.4-1+deb12u2DEBIAN-CVE-2025-69224
Debian:13python-aiohttp3.11.16-1+deb13u1DEBIAN-CVE-2025-69224
Debian:14python-aiohttp3.13.3-1DEBIAN-CVE-2025-69224
PyPIaiohttp3.13.3PYSEC-2026-1099
PyPIaiohttp3.13.3GHSA-69f9-5gxw-wvc2
Ubuntu:25.10python-aiohttp3.11.16-1ubuntu0.1UBUNTU-CVE-2025-69224

Affected products (as reported)

VendorProductVersions
aio-libs aiohttp < 3.13.3

Weakness: CWE-444 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

References