{"id":"CVE-2026-39378","aliases":["GHSA-7jqv-fw35-gmx9","PYSEC-2026-2230"],"url":"https://o3.security/vulnerability/CVE-2026-39378","summary":"nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding","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.","published":"2026-04-21T00:17:00.684Z","modified":"2026-08-05T03:47:30.361750092Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"nbconvert","fixedVersion":"7.17.1"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/jupyter/nbconvert/releases/tag/v7.17.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39378.json"},{"type":"ADVISORY","url":"https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39378"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-05T03:47:30.361750092Z"}}