GHSA-3wq7-rqq7-wx6j
AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS
At a glance
- Published
- Updated
- CVE
- CVE-2026-34517
- Aliases
- PYSEC-2026-2099
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U
Description
### Summary For some multipart form fields, aiohttp read the entire field into memory before checking client_max_size. ### Impact 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
Affected packages
| Package | Versions |
|---|---|
| PyPI · aiohttp | introduced 0, fixed 3.13.4 |
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6j WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-34517 ADVISORY
- https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145 WEB
- https://github.com/aio-libs/aiohttp PACKAGE
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |