PT-2026-33878 · Jupyter · Nconvert

Published 2026-04-21 · Updated 2026-04-21 · CVE-2026-39377

NVD

CVSS v3.1

6.5

Medium

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. Versions 6.5 through 7.17.0 allow arbitrary file writes to locations outside the intended output directory when processing notebooks containing crafted cell attachment filenames. The ExtractAttachmentsPreprocessor passes attachment filenames directly to the filesystem without sanitization, enabling path traversal attacks. This vulnerability provides complete control over both the destination path and file extension. Version 7.17.1 contains a patch.

Fix

Path traversal

Weakness Enumeration

CWE-73

CWE-22

Related Identifiers

CVE-2026-39377

Affected Products

Nconvert

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-39377 · Security Note
• https://github.com/jupyter/nbconvert/releases/tag/v7.17.1 · Note
• https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg · Note