# CVE-2026-39378

> Vulnerability · severity: **MEDIUM** (CVSS 6.5).

## 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.

## Key facts

- **CVE ID:** CVE-2026-39378
- **Published:** 2026-04-21
- **CVSS severity:** MEDIUM
- **CVSS base score:** 6.5
- **CWE codes:** CWE-22, CWE-73

## Affected products

- `jupyter:nbconvert`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39378

## Citation

> AI Analytics. CVE-2026-39378. Retrieved 2026-07-20 from https://api.ai-analytics.org/cve/CVE-2026-39378. Derived from NIST NVD. Licensed CC0.

---

*[Dataset catalog](https://api.ai-analytics.org/datasets/) · [AI Analytics](https://api.ai-analytics.org/) · CC0 1.0*