{"affected":[{"product":"aiohttp","source":"CNA: GitHub_M","vendor":"aio-libs","versions":[{"status":"affected","version":"< 3.14.4"}]}],"cveId":"CVE-2026-128126","cwes":["CWE-407"],"description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Request.post() does not limit the number of fields in a URL-encoded form body, and inserting many repeated keys into MultiDict takes quadratic time on the event loop. A remote attacker can send a form POST within client_max_size to a handler that calls Request.post() and block the event loop. This issue is fixed in version 3.14.4.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":8.7,"severity":"high","source":"CNA: GitHub_M","vector":"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","version":"4.0"}],"modifiedAt":1794601677071,"publishedAt":1794601677071,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xgw8-8ccx-rmqh"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13738"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13741"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/615fec3d4f088f30d2ee72cad760152e92aa1c53"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/8b0100572936df28977b9de8a6cc7e464c0b521e"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"}],"remediation":[],"revision":"f269382b923b28acd3f83cc93fe26a2b2fa6a4abd4f1039ce6f7479d574ddf69","sources":[{"modifiedAt":1794601677071,"name":"CNA: GitHub_M","retrievedAt":1794604207856,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128126"}],"ssvc":null,"status":"published","title":"AIOHTTP: Too many URL-encoded form fields block the event loop","updatedAt":1794604207856}