PyPI/aiohttp CVE-2026-34525: medium 5.3, EPSS 0.30%
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.
Action: Upgrade aiohttp to 3.13.4 or later.
pip install aiohttp==3.13.4Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 3.13.4 | - |
Fixed versions
| 3.13.4 |
Sources
- osv: PYSEC-2026-2103
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
- https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67
CVE-2026-34525 · published · modified · JSON