Vulnerability · Published Jun 2, 2026 · Assigned by GitHub_M
CVE-2026-47265AIOHTTP vulnerable to cross-origin redirect with per-request cookies
Medium 6.6
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 0.1% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | python-aiohttp | 3.8.4-1+deb12u2 | DEBIAN-CVE-2026-47265 |
| Debian:13 | python-aiohttp | no fix listed | DEBIAN-CVE-2026-47265 |
| Debian:14 | python-aiohttp | 3.14.0-1 | DEBIAN-CVE-2026-47265 |
| PyPI | aiohttp | 3.14.0 | PYSEC-2026-2105 |
| PyPI | aiohttp | 3.14.0 | GHSA-hg6j-4rv6-33pg |
| Ubuntu:25.10 | python-aiohttp | no fix listed | UBUNTU-CVE-2026-47265 |
| Ubuntu:26.10 | python-aiohttp | no fix listed | UBUNTU-CVE-2026-47265 |
Affected products (as reported)
Weakness: CWE-346 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U