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GHSA-4c99-qj7h-p3vg

MediumCVSS 6.5 / 10
Published Apr 21, 2026·Last modified Apr 30, 2026
Affected Components(0)

No affected components available

Description

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:

c. ExtractAttachmentsPreprocessor.enabled = False
Risk Scores
Base Score
6.5

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a high impact on the integrity of the data.

Threat Intelligence
6.0

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.27%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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