For some multipart form fields, aiohttp read the entire field into memory before checking clientmaxsize.
If an application uses Request.post() an attacker can send a specially crafted multipart request to force significant temporary memory allocation even when the request is ultimately rejected.
Patch: https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145
{
"github_reviewed": true,
"github_reviewed_at": "2026-04-01T21:47:07Z",
"nvd_published_at": "2026-04-01T21:16:59Z",
"severity": "LOW",
"cwe_ids": [
"CWE-770"
]
}