What is CVE-2026-39378?

CVE-2026-39378 is a medium-severity vulnerability in Jupyter Nbconvert, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-04-21.

How severe is CVE-2026-39378?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Path Traversal in Jupyter Nbconvert

CVE-2026-39378

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…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.003 (22.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Jupyter Nbconvert — versions >= 6.5, < 7.17.1

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
security-advisories@github.com (Product, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-39378?: CVE-2026-39378 is a medium-severity vulnerability in Jupyter Nbconvert, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-04-21.
How severe is CVE-2026-39378?: Medium severity. CVSS v3 base score is 6.5 out of 10.