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 AIOHTTPNOEXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections.
Patch: https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a
{ "github_reviewed_at": "2025-07-14T19:33:31Z", "cwe_ids": [ "CWE-444" ], "nvd_published_at": "2025-07-14T21:15:27Z", "severity": "LOW", "github_reviewed": true }