PyPI/aiohttp CVE-2026-34516: high 7.5, EPSS 0.61%

AIOHTTP has a Multipart Header Size Bypass

Action: Upgrade aiohttp to 3.13.4 or later.

pip install aiohttp==3.13.4

Affected

Fixed versions

Sources

• osv: GHSA-m5qp-6w8w-w647
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647
• https://nvd.nist.gov/vuln/detail/CVE-2026-34516
• https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f
• https://github.com/aio-libs/aiohttp
• https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4

CVE-2026-34516 · published 2026-04-01T21:43:07Z · modified 2026-09-10T03:51:02.372876858Z · JSON