AI and data stack advisories

Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

JupyterGHSA-7jqv-fw35-gmx9

nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding

Jupyter

CVE-2026-39378 · Published Apr 21, 2026 · updated Sep 10, 2026

Medium6.5
Fix: upgrade to 7.17.1 or later
GitHub advisory

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).

Affected versions

PackageAffectedFixed in
nbconvert
PyPI
>= 6.5.0, < 7.17.17.17.1
Details and references
CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Severity from
GitHub (reviewed advisory)
Weakness
CWE-22, CWE-23
Also known as
CVE-2026-39378, PYSEC-2026-2230

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