CVE-2026-34516
HIGH7.5EPSS 0.02%AIOHTTP has a Multipart Header Size Bypass
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, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. 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:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-34516
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-34516
- PATCHhttps://github.com/aio-libs/aiohttp
- WEBhttps://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f
- WEBhttps://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- WEBhttps://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647