medium5.3
CVE-2026-34525
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python.
Impact
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. 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/53e2e6fc58b89c6185be7820bd2c9f40216b3000
- https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67
- https://github.com/advisories/GHSA-c427-h43c-vf67
- https://nvd.nist.gov/vuln/detail/CVE-2026-34525