---
id: CVE-2026-114140
title: 'nbconvert: File write via path traversal in cell output filenames'
summary: >-
  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 …
severity: high
cvss: 8.8
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'
cvssSource: cna
cwe:
  - CWE-22
vendor: jupyter
product: nbconvert
affected:
  - 'nbconvert >= 5.4.0, < 7.17.2'
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T20:19:50.116Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114140'
references:
  - url: >-
      https://github.com/jupyter/nbconvert/security/advisories/GHSA-pjvx-prjx-h659
    label: >-
      https://github.com/jupyter/nbconvert/security/advisories/GHSA-pjvx-prjx-h659
  - url: >-
      https://github.com/jupyter/nbconvert/commit/ce4bd99aec31d81d759fa8eeb8643179392ec66f
    label: >-
      https://github.com/jupyter/nbconvert/commit/ce4bd99aec31d81d759fa8eeb8643179392ec66f
  - url: 'https://github.com/jupyter/nbconvert/releases/tag/v7.17.2'
    label: 'https://github.com/jupyter/nbconvert/releases/tag/v7.17.2'
tags:
  - cve.org
ingestedAt: '2026-10-21T21:13:32.888Z'
---

## Overview

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.

## Affected

- `nbconvert >= 5.4.0, < 7.17.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.