{"id":"UBUNTU-CVE-2026-5422","details":"A path traversal vulnerability exists in jupyter-server version 2.17.0 due to an incorrect root directory boundary check in the _get_os_path() function within jupyter_server/services/contents/fileio.py. The check uses startswith(root) without appending a trailing path separator, allowing sibling directories with names starting with the same prefix as root_dir to bypass the check. Additionally, the to_os_path() function in utils.py does not strip \"..\" from path parts, enabling traversal sequences to bypass the vulnerable check. This vulnerability can lead to unauthorized read/write access to files in sibling directories, potentially exposing sensitive data in shared hosting environments.","modified":"2026-06-12T09:04:22.020160556Z","published":"2026-06-02T10:16:00Z","upstream":["CVE-2026-5422"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-5422"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-5422"},{"type":"REPORT","url":"https://huntr.com/bounties/24a36953-6490-466f-8cb2-a90d1ca56e0f"}],"affected":[{"package":{"name":"jupyter-server","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/jupyter-server?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.2-1","1.13.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.13.1-1","binary_name":"jupyter-server"},{"binary_version":"1.13.1-1","binary_name":"python3-jupyter-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5422.json"}},{"package":{"name":"jupyter-server","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/jupyter-server?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.23.3-1","1.23.3-2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.23.3-2","binary_name":"jupyter-server"},{"binary_name":"python3-jupyter-server","binary_version":"1.23.3-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5422.json"}},{"package":{"name":"jupyter-server","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/jupyter-server?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.14.2-5","2.15.0-1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.15.0-1","binary_name":"jupyter-server"},{"binary_version":"2.15.0-1","binary_name":"python3-jupyter-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5422.json"}},{"package":{"name":"jupyter-server","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/jupyter-server?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.15.0-1","2.17.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyter-server","binary_version":"2.17.0-1"},{"binary_name":"python3-jupyter-server","binary_version":"2.17.0-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5422.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}