CVE-2026-34525
MEDIUM5.3EPSS 0.16%AIOHTTP accepts duplicate Host headers
Published: 4/1/2026Modified: 6/1/2026
Description
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 (2)
- Debian/python-aiohttpfrom 0
- PyPI/aiohttpfrom 0, < 3.13.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-34525
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-34525
- PATCHhttps://github.com/aio-libs/aiohttp
- WEBhttps://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000
- WEBhttps://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349
- WEBhttps://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- WEBhttps://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67