Affected: Homebrew: jupyterlab

# Arbitrary File Write via Path Traversal in Cell Attachment Filenames

## Summary

nbconvert allows 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.

## Impact

This vulnerability allows writing files with arbitrary content to arbitrary filesystem locations, limited only by the permissions of the process running nbconvert. The attacker controls: - Full destination path (via `../` traversal) - Filename - File extension - File content

## Patches

- upgrade to nbconvert v7.17.1

## Workarounds

disable ExtractAttachmentsPreprocessor by setting:

```python c. ExtractAttachmentsPreprocessor.enabled = False ```

Affected: CleanStart: tensorflow-gpu-jupyter

Security vulnerability affects the tensorflow-gpu-jupyter package. This issue is resolved in later releases. See references for vulnerability details.

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.

Affected: PyPI: nbconvert

# Arbitrary File Write via Path Traversal in Cell Attachment Filenames

## Summary

nbconvert allows 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.

## Impact

This vulnerability allows writing files with arbitrary content to arbitrary filesystem locations, limited only by the permissions of the process running nbconvert. The attacker controls: - Full destination path (via `../` traversal) - Filename - File extension - File content

## Patches

- upgrade to nbconvert v7.17.1

## Workarounds

disable ExtractAttachmentsPreprocessor by setting:

```python c. ExtractAttachmentsPreprocessor.enabled = False ```

Affected: openEuler:24.03-LTS: python-nbconvert

The nbconvert tool, jupyter nbconvert, converts notebooks to various other formats via Jinja templates. The nbconvert tool allows you to convert an .ipynb notebook file into various static formats including HTML, LaTeX, PDF, Reveal JS, Markdown (md), ReStructured Text (rst) and executable script. Security Fix(es):

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.(CVE-2026-39377)

The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. In versions 6.5 through 7.17.0, when `HTMLExporter.embed_images=True`, nbconvert's markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML. nbconvert 7.17.1 contains a fix. As a workaround, do not enable `HTMLExporter.embed_images`; it is not enabled by default.(CVE-2026-39378)

jupyter-nbconvert-7.17.1-1.1 on GA media

Affected: PyPI: nbconvert

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.

Affected: Ubuntu:18.04:LTS: nbconvert, Ubuntu:20.04:LTS: nbconvert, Ubuntu:22.04:LTS: nbconvert, Ubuntu:24.04:LTS: nbconvert, Ubuntu:25.10: nbconvert, Ubuntu:26.04:LTS: nbconvert

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.