{"affected":[{"product":"aiohttp","source":"CNA: GitHub_M","vendor":"aio-libs","versions":[{"status":"affected","version":"< 3.14.4"}]}],"cveId":"CVE-2026-128129","cwes":["CWE-770"],"description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, aiohttp buffers all additional connection data received while a request marked for upgrade, such as a WebSocket handshake, is being handled, without a size limit or flow control. A remote attacker can stream data behind an upgrade request to a handler that does not immediately accept or reject the upgrade and cause unbounded memory consumption. This issue is fixed in version 3.14.4.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":8.2,"severity":"high","source":"CNA: GitHub_M","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}],"modifiedAt":1794605119830,"publishedAt":1794602025088,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-pw86-h8fm-j323"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13501"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13511"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/3d850ee9b92573c7e913821cbcb96005beb3f4df"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/c207cadb257e0959b192ffca0548eca8c71eb96a"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"}],"remediation":[],"revision":"25d7e27494f95685fc777e3f36303b5f6f282c12c49216efb286d2a769a1ddb0","sources":[{"modifiedAt":1794605119830,"name":"CNA: GitHub_M","retrievedAt":1794607767933,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128129"}],"ssvc":{"assessedAt":1794605112290,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"AIOHTTP: Unbounded buffering of data received during an upgrade request","updatedAt":1794607767933}