{"id":"UBUNTU-CVE-2026-39378","details":"The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. In versions 6.5 through 7.17.0, when `HTMLExporter.embed_images=True`, nbconvert's markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML. nbconvert 7.17.1 contains a fix. As a workaround, do not enable `HTMLExporter.embed_images`; it is not enabled by default.","modified":"2026-05-20T16:25:38.357288529Z","published":"2026-04-21T01:16:00Z","upstream":["CVE-2026-39378"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-39378"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-39378"},{"type":"REPORT","url":"https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9"}],"affected":[{"package":{"name":"nbconvert","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.0-4","5.3.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.3.1-1","binary_name":"jupyter-nbconvert"},{"binary_name":"python-nbconvert","binary_version":"5.3.1-1"},{"binary_name":"python3-nbconvert","binary_version":"5.3.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}},{"package":{"name":"nbconvert","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.4-2ubuntu2","5.6.0-1","5.6.0-2","5.6.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyter-nbconvert","binary_version":"5.6.1-1"},{"binary_name":"python3-nbconvert","binary_version":"5.6.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}},{"package":{"name":"nbconvert","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.6.1-3","6.1.0-1","6.3.0-1","6.4.0-1"],"ecosystem_specific":{"binaries":[{"binary_version":"6.4.0-1","binary_name":"jupyter-nbconvert"},{"binary_version":"6.4.0-1","binary_name":"python3-nbconvert"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}},{"package":{"name":"nbconvert","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.5.3-4","6.5.3-5"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyter-nbconvert","binary_version":"6.5.3-5"},{"binary_version":"6.5.3-5","binary_name":"python3-nbconvert"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}},{"package":{"name":"nbconvert","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.16.6-1"],"ecosystem_specific":{"binaries":[{"binary_version":"7.16.6-1","binary_name":"jupyter-nbconvert"},{"binary_name":"python3-nbconvert","binary_version":"7.16.6-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}},{"package":{"name":"nbconvert","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/nbconvert?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.16.6-1","7.17.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyter-nbconvert","binary_version":"7.17.0-1"},{"binary_version":"7.17.0-1","binary_name":"python3-nbconvert"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39378.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}