{"action":"Upgrade aiohttp to 3.13.4 or later.","affected":[{"fixed":"3.13.4","introduced":"0"}],"component":"aiohttp","cve_ids":["CVE-2026-34520"],"ecosystem":"PyPI","epss":0.00676,"exploited":false,"fixed_versions":["3.13.4"],"ghsa_id":"GHSA-63hf-3vf5-4wqf","id":"tcs_01M5KGXG2D72PFQVEPPWXBJJS3","modified_at":"2026-07-13T07:15:12.708711382Z","published_at":"2026-04-01T21:17:00.333Z","references":["https://osv.dev/vulnerability/PYSEC-2026-2102","https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4","https://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4","https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hf-3vf5-4wqf"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"PYSEC-2026-2102","url":"https://osv.dev/vulnerability/PYSEC-2026-2102"}],"summary":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in resp"}