Improper access control in aiohttp - CVE-2026-47265
Published: June 2, 2026
Vulnerability identifier: #VU133241
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-47265
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: aio-libs
Affected software:
aiohttp
aiohttp
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper access control in request redirect handling when following a cross-origin redirect after setting per-request cookies. A remote attacker can control a redirect to disclose sensitive information.
The issue occurs only when cookies are supplied through the per-request cookies parameter.
How to mitigate CVE-2026-47265
Install security update from vendor's website.