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.
Published: 2026-10-21
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 22 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

threat_severity

Important


Thu, 22 Oct 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Jupyter
Jupyter nbconvert
Vendors & Products Jupyter
Jupyter nbconvert

Wed, 21 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
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.
Title nbconvert: File write via path traversal in cell output filenames
Weaknesses CWE-22
References
Metrics cvssV4_0

{'score': 8.8, 'vector': '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'}


Subscriptions

Jupyter Nbconvert
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-21T20:19:50.116Z

Reserved: 2026-10-20T21:53:58.473Z

Link: CVE-2026-114140

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T21:17:56.520

Modified: 2026-10-21T21:17:56.520

Link: CVE-2026-114140

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-21T20:19:50Z

Links: CVE-2026-114140 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-22T10:30:04Z

Weaknesses