{"id":"CVE-2026-125111","published":"2026-11-09T22:18:42.433","lastModified":"2026-11-09T22:18:42.433","description":"Rack is a modular Ruby web server interface. Prior to 2.2.25, 3.1.23, and 3.2.8, Rack::Multipart::Parser can retain parsed data in its internal StringScanner buffer when reads end inside or immediately after multipart headers. An unauthenticated attacker can align many small parts with rack.multipart.buffer_size boundaries so the buffer grows with the request despite per-field, header, and preamble limits, causing a worker to exhaust memory. The attack requires only a well-formed multipart body and affects applications that parse multipart requests. This issue is fixed in versions 2.2.25, 3.1.23, and 3.2.8.","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-400"],"vendors":[],"products":[],"references":[{"url":"https://github.com/rack/rack/commit/244e75a840cee0823f86d5d01dc374505a8abed8","tags":[]},{"url":"https://github.com/rack/rack/commit/2eaa5b1026a03a43b6537b1a0b233707ba887702","tags":[]},{"url":"https://github.com/rack/rack/commit/c9b4698595050838342bd3b5a0fc9ab908065f8f","tags":[]},{"url":"https://github.com/rack/rack/security/advisories/GHSA-5v64-555j-wjxm","tags":[]}],"exploitRefs":[{"url":"https://github.com/rack/rack/commit/244e75a840cee0823f86d5d01dc374505a8abed8","tags":[]},{"url":"https://github.com/rack/rack/commit/2eaa5b1026a03a43b6537b1a0b233707ba887702","tags":[]},{"url":"https://github.com/rack/rack/commit/c9b4698595050838342bd3b5a0fc9ab908065f8f","tags":[]},{"url":"https://github.com/rack/rack/security/advisories/GHSA-5v64-555j-wjxm","tags":[]}],"hasPoc":true,"ai":null}