Vulnerability · Published Jan 5, 2026 · Assigned by GitHub_M

CVE-2025-69225AIOHTTP Regex Mismatch Allows Unicode in ASCII-Only Protocol Fields

Low 2.7

In plain English

A low-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 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)2.7Low
Exploit odds (30 days)0.3%top 79.2% 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 contain parser logic which allows non-ASCII decimals to be present in the Range header. There is no known impact, but there is the possibility that there's a method to exploit a request smuggling vulnerability. This issue is fixed in version 3.13.3.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23py3-aiohttp3.13.3-r0ALPINE-CVE-2025-69225
Alpine:v3.24py3-aiohttp3.13.3-r0ALPINE-CVE-2025-69225
Debian:12python-aiohttp3.8.4-1+deb12u2DEBIAN-CVE-2025-69225
Debian:13python-aiohttp3.11.16-1+deb13u1DEBIAN-CVE-2025-69225
Debian:14python-aiohttp3.13.3-1DEBIAN-CVE-2025-69225
PyPIaiohttp3.13.3PYSEC-2026-1109
PyPIaiohttp3.13.3GHSA-mqqc-3gqh-h2x8
Ubuntu:25.10python-aiohttp3.11.16-1ubuntu0.1UBUNTU-CVE-2025-69225

Affected products (as reported)

VendorProductVersions
aio-libs aiohttp < 3.13.3

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

References