CVE-2026-114140 nbconvert: File write via path traversal in cell output filenames
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-114140?
CVE-2026-114140 is a high-severity vulnerability in jupyter nbconvert, published on 21 Oct 2026.
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-114140?
2 open source packages ship an affected version, including nbconvert.
| Package | Affected | Fixed in |
|---|---|---|
nbconvert PyPI | From 5.4.0 | 7.17.2 |
nbconvert PyPI | From 5.4.0 | 7.17.2 |
How do I fix CVE-2026-114140?
Upgrade nbconvert to 7.17.2 or later.
Is CVE-2026-114140 being exploited?
There is no known exploitation of CVE-2026-114140 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-114140, GHSA-pjvx-prjx-h659, UBUNTU-CVE-2026-114140.