{"affected":[{"product":"aiohttp","source":"CNA: GitHub_M","vendor":"aio-libs","versions":[{"status":"affected","version":"< 3.14.4"}]}],"cveId":"CVE-2026-128131","cwes":["CWE-400","CWE-407"],"description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, aiohttp decompresses each member of a payload containing many concatenated gzip, deflate, or zstd streams by passing the entire remaining input to a new decompressor, causing quadratic CPU use. Empty members produce no output, so client_max_size and output backpressure do not limit the work. A remote attacker can block a server event loop with a crafted compressed request body or WebSocket message, and a malicious server can similarly block a client. 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":1794602386745,"publishedAt":1794602386745,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/aio-libs/aiohttp/security/advisories/GHSA-h4cc-hm5h-fmm9"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13362"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/pull/13391"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/d041d4d0fd48c3f0832084d33be16cf1c4835f85"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/commit/d925a80539ffd227da1d93ab4a5bff123cc777db"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"}],"remediation":[],"revision":"98c71387886804768f69d4ea9788e223a037308fe7f423aecea4a0be4f67fa58","sources":[{"modifiedAt":1794602386745,"name":"CNA: GitHub_M","retrievedAt":1794604213467,"url":"https://www.cve.org/CVERecord?id=CVE-2026-128131"}],"ssvc":null,"status":"published","title":"AIOHTTP: Concatenated compressed streams cause excessive CPU use","updatedAt":1794604213467}