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.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:HI:NA:N6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:NInput Validation