CVE-2026-39378
Published:April 21, 2026
Updated:April 23, 2026
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.
Affected Packages
nbconvert (CONDA):
Affected version(s) >=6.5.0 <7.17.1Fix Suggestion:
Update to version 7.17.1https://github.com/jupyter/nbconvert.git (GITHUB):
Affected version(s) >=v7.2.0 <v7.17.1Fix Suggestion:
Update to version v7.17.1nbconvert (PYTHON):
Affected version(s) >=6.5.0 <7.17.1Fix Suggestion:
Update to version 7.17.1Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.04
