high7.5
CVE-2026-34513
AIOHTTP Affected by Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector
Impact
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an unbounded DNS cache could result in excessive memory usage possibly resulting in a DoS situation. 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/c4d77c3533122be353b8afca8e8675e3b4cbda98
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hcc4-c3v8-rx92
- https://github.com/advisories/GHSA-hcc4-c3v8-rx92
- https://nvd.nist.gov/vuln/detail/CVE-2026-34513