{"id":"DEBIAN-CVE-2026-44727","details":"Jupyter Server is the backend for Jupyter web applications. Prior to 2.20, the nbconvert HTTP handlers in jupyter_server render user-authored notebook HTML under the Jupyter origin without a sandbox directive in their Content-Security-Policy. Combined with nbconvert.HTMLExporter's default non-sanitizing behavior, a notebook carrying an HTML payload in a display_data output triggers stored XSS with cookie access, full /api/* authority, and kernel RCE. This vulnerability is fixed in 2.20.","modified":"2026-09-14T17:03:41.427961143Z","published":"2026-06-22T21:16:24.260Z","upstream":["CVE-2026-44727"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-44727"}],"affected":[{"package":{"name":"jupyter-server","ecosystem":"Debian:12","purl":"pkg:deb/debian/jupyter-server?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.23.3-1","1.23.3-2","2.14.0-1","2.14.2-1","2.14.2-2","2.14.2-3","2.14.2-4","2.14.2-5","2.15.0-1","2.17.0-1","2.20.0-1","2.20.0-2","2.20.0-3","2.9.1-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44727.json"}},{"package":{"name":"jupyter-server","ecosystem":"Debian:13","purl":"pkg:deb/debian/jupyter-server?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.15.0-1","2.17.0-1","2.20.0-1","2.20.0-2","2.20.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44727.json"}},{"package":{"name":"jupyter-server","ecosystem":"Debian:14","purl":"pkg:deb/debian/jupyter-server?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.20.0-1"}]}],"versions":["2.15.0-1","2.17.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44727.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"}]}