[ CVE-2026-114140 · Published 21 Oct 2026 ]
nbconvert: Arbitrary file write through path traversal in cell output filenames when exporting to md, latex, rst and asciidoc
[ Description ]Official description
The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. From 5.4.0 until 7.17.2, ExtractOutputPreprocessor in nbconvert/preprocessors/extractoutput.py joins the attacker-controlled cell output metadata filename to output_files_dir without limiting the result to the intended directory. When a victim converts a malicious notebook with the markdown, LaTeX, reStructuredText, or AsciiDoc exporter, path traversal in the output filename can write attacker-controlled output data to arbitrary locations accessible to the victim. Running the notebook cell again replaces the malicious output metadata, but merely converting the supplied notebook does not. This issue is fixed in version 7.17.2.
[ Fixes ]Fixes and patches
- nbconvert 7.17.2Fixed version · GitHub Advisories · pip package nbconvert: upgrade to 7.17.2 or later (affected >= 5.4.0, <= 7.17.1)
[ Packages ]Affected open-source packages
- nbconvert pipAffected >= 5.4.0, <= 7.17.1 · fixed in 7.17.2 · GHSA-pjvx-prjx-h659