{"id":"CVE-2026-69243","aliases":["GHSA-mfx4-hv73-q22v","PYSEC-2026-3546"],"url":"https://o3.security/vulnerability/CVE-2026-69243","summary":"AIOHTTP: HTTP request smuggling via WebSocket upgrade","details":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades. If using the server-side component, an attacker may be able to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. A WebSocket upgrade request with a body could cause the parser to switch protocols before the complete request body was received, leaving trailing bytes to be handled as upgraded-protocol or pipelined data rather than normal HTTP body data. This issue is fixed in version 3.14.2.","published":"2026-08-03T20:45:43.406Z","modified":"2026-09-14T18:27:02.367054300Z","cvss":null,"epss":{"score":0.00431,"percentile":0.36712,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"aiohttp","fixedVersion":"3.14.2"}],"fix":{"url":"https://github.com/aio-libs/aiohttp/commit/6ae358f0983c3f4d6f67692b2f8e65dc8e091c98","label":"aio-libs/aiohttp@6ae358f"},"references":[{"type":"WEB","url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.14.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69243.json"},{"type":"ADVISORY","url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mfx4-hv73-q22v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-69243"},{"type":"FIX","url":"https://github.com/aio-libs/aiohttp/commit/6ae358f0983c3f4d6f67692b2f8e65dc8e091c98"},{"type":"FIX","url":"https://github.com/aio-libs/aiohttp/pull/13017"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-14T18:27:02.367054300Z"}}