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CVE-2026-39378

nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding

Published: Apr 21, 2026Updated: Apr 23, 2026 Sources: CVE List NVDCWE-22
NVD MITRE
6.5CVSSMEDIUM
EPSS Score
0.3%
Top 78.0%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only

Description

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-22CWE-73

Affected Products

nbconvertjupyter
Mixed
AI / ML / notebook-mlops
jupyteross-projectAI / MLaka notebook, jupyter server, jupyterlab

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Workaround Available

MITRE ATT&CK

2 techniques
Collection
Discovery
View detailed technique mapping

References

https://github.com/jupyter/nbconvert/releases/tag/v7.17.1
github.com
https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9
github.com

Timeline

Published
Apr 21, 2026
Last Updated
Apr 23, 2026

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