{"id":"DEBIAN-CVE-2026-35397","details":"Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, a path traversal vulnerability in the REST API allows an authenticated user to escape the configured root_dir and access sibling directories whose names begin with the same prefix as the root_dir. For example, with a root_dir named \"test\", the API permits access to a sibling directory named \"testtest\" through a crafted request to the /api/contents endpoint using encoded path components. An attacker can read, write, and delete files in affected sibling directories. Multi-tenant deployments using predictable naming schemes are particularly at risk, as a user with a directory named \"user1\" could access directories for user10 through user19 and beyond. A user who can choose a single-character folder name could gain access to a significant number of sibling directories.   Version 2.18.0 contains a fix. As a workaround, ensure folder names do not share a common prefix with any sibling directory.","modified":"2026-09-01T16:06:41.049782299Z","published":"2026-05-05T20:16:38.223Z","upstream":["CVE-2026-35397"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-35397"}],"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/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-35397.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/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-35397.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/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-35397.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}