CVE-2026-39377 — nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames
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 locati…
Published: 2026-04-21 · CVSS: 6.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7