CVE-2026-39377 (GCVE-0-2026-39377)

Vulnerability from cvelistv5 – Published: 2026-04-21 00:14 – Updated: 2026-04-21 19:49
VLAI?
Title
nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames
Summary
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.
Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • CWE-73 - External Control of File Name or Path
Assigner
References
Impacted products
Vendor Product Version
jupyter nbconvert Affected: >= 6.5, < 7.17.1
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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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