{"id":"DEBIAN-CVE-2026-115927","details":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.6.0, Tornado decodes HTTP/1.1 chunked transfer encoding by processing body data that has already arrived without yielding to the event loop. A remote unauthenticated peer can send millions of one-byte chunks to monopolize the process event loop and stall every other connection served by that process, while lowering max_body_size only limits the duration of each request. For handlers that do not use @stream_request_body, retaining each chunk as a separate object can consume roughly twenty times the received body size, and SimpleAsyncHTTPClient has the same event-loop behavior when reading a response from a malicious server. This issue is fixed in version 6.6.0.","modified":"2026-10-27T19:00:42.826570803Z","published":"2026-10-26T20:17:52.397Z","upstream":["CVE-2026-115927"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-115927"}],"affected":[{"package":{"name":"python-tornado","ecosystem":"Debian:12","purl":"pkg:deb/debian/python-tornado?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.2.0-3","6.2.0-3+deb12u1","6.2.0-3+deb12u2","6.2.0-3+deb12u3","6.2.0-3+deb12u4","6.3.2-1","6.4.0-1","6.4.0-2","6.4.1-1","6.4.1-2","6.4.1-3","6.4.2-1","6.4.2-2","6.4.2-3","6.5.2-1","6.5.2-2","6.5.2-3","6.5.4-0.1","6.5.4-1","6.5.5-1","6.5.5-2","6.5.5-3","6.5.5-4","6.5.5-5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115927.json"}},{"package":{"name":"python-tornado","ecosystem":"Debian:13","purl":"pkg:deb/debian/python-tornado?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.4.2-3","6.4.2-3+deb13u1","6.4.2-3+deb13u2","6.5.2-1","6.5.2-2","6.5.2-3","6.5.4-0.1","6.5.4-1","6.5.5-1","6.5.5-2","6.5.5-3","6.5.5-4","6.5.5-5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115927.json"}},{"package":{"name":"python-tornado","ecosystem":"Debian:14","purl":"pkg:deb/debian/python-tornado?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.4.2-3","6.5.2-1","6.5.2-2","6.5.2-3","6.5.4-0.1","6.5.4-1","6.5.5-1","6.5.5-2","6.5.5-3","6.5.5-4","6.5.5-5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-115927.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}