CVE-2026-39378
nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-22 CWE-73 |
| Vendor | jupyter |
| Product | nbconvert |
| Published | Apr 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
jupyter / nbconvert
>= 6.5, < 7.17.1