VULNERABILITY INTELLIGENCE
CVE-2026-39378
CVSS score6.5 MEDIUM
EPSS probability0.31%
CISA KEVNot currently listed
Published2026-04-21
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
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.
Weakness classification
- security-advisories@github.com: CWE-22
Primary references
- security-advisories@github.com — Product
- security-advisories@github.com — Mitigation, Vendor Advisory