jupyter nbconvert up to 7.17.0 Jinja Template path traversal

Summaryinfo

A vulnerability classified as critical was found in jupyter nbconvert up to 7.17.0. The affected element is an unknown function of the component Jinja Template Handler. The manipulation results in path traversal. This vulnerability is identified as CVE-2026-39377. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in jupyter nbconvert up to 7.17.0. It has been classified as critical. Affected is an unknown function of the component Jinja Template Handler. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-39377 since 04/06/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

The vulnerability scanner Nessus provides a plugin with the ID 309097 (Linux Distros Unpatched Vulnerability : CVE-2026-39377), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.17.1 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (309097). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• jupyter

Name

• nbconvert

Version

• 7.0
• 7.1
• 7.2
• 7.3
• 7.4
• 7.5
• 7.6
• 7.7
• 7.8
• 7.9
• 7.10
• 7.11
• 7.12
• 7.13
• 7.14
• 7.15
• 7.16
• 7.17.0

Website

• Product: https://github.com/jupyter/nbconvert/

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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