GitHub Advisoryadvisory · PyPI

GHSA-7jqv-fw35-gmx9 nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding

MEDIUM Published 2026-04-21 Modified 2026-04-21 Official page ↗
Aliases
CVE-2026-39378
Ecosystem
PyPI
Packages
nbconvert
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Weaknesses
CWE-22, CWE-23
Reviewed
2026-04-21

Affected packages

• PyPI nbconvert: >= 6.5.0, < 7.17.1 → fixed in 7.17.1

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).

Related

Alias · CVE (1)

  • CVE-2026-39378 The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. vulnerability

Weakness · CWE (2)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness
  • CWE-23 Relative Path Traversal weakness

References