jupyter/nbconvert · Security
nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding
- GHSA ID
- GHSA-7jqv-fw35-gmx9
- CVE ID
- CVE-2026-39378
- Severity
- medium
- Published
- Updated
- CVSS
- 6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- CVSS v3
- 6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Description
Summary
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.
Patches
Upgrade to nbconvert 7.17.1
Workarounds
Do not enable HTMLExporter.embed_images (it is not enabled by default).
CWEs
- CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-23 · Relative Path Traversal