medium5.3
CVE-2026-34517
AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS
Impact
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, for some multipart form fields, aiohttp read the entire field into memory before checking client_max_size. This issue has been patched in version 3.13.4.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | aiohttp | <= 3.13.3 | 3.13.4 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Aiohttp | Aiohttp | before 3.13.4 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6j
- https://github.com/advisories/GHSA-3wq7-rqq7-wx6j
- https://nvd.nist.gov/vuln/detail/CVE-2026-34517