nbconvert vulnerable to cross-site scripting (XSS) via multiple exploit paths
Priority LOW 36CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.
Summary
The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
Why it matters now
EPSS 0.0152 74th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed nbconvert (PyPI): 6.5.1
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| jupyterlab | nbconvert | up to 6.2 | — | No fix listed | CNA |
| — | nbconvert (PyPI) | before 6.5.1 | 6.5.1 | Patch available | GHSA-9jmq-rx5f-8jwq |
- nbconvert Vendorjupyterlab Affected up to 6.2 Fixed in — No fix listed CNA
- nbconvert (PyPI) Vendor— Affected before 6.5.1 Fixed in 6.5.1 Patch available GHSA-9jmq-rx5f-8jwq
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:jupyter:nbconvert:*:*:*:*:*:python:*:* | up to 6.2.0 | Vulnerable | jupyterlab |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
- cpe:2.3:a:jupyter:nbconvert:*:*:*:*:*:python:*:* Versions up to 6.2.0 Vulnerable ·jupyterlab
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
Remediation
- Fix · GHSA-9jmq-rx5f-8jwq nbconvert (PyPI) Fixed in 6.5.1 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-32862
- 2026-10-03 Alias added: GHSA-9jmq-rx5f-8jwq
References
Advisory 2
More jupyterlab Nbconvert vulnerabilities
- TI-2025-33005 nbconvert has an uncontrolled search path that leads to unauthorized code execution on Windows CVSS 4.0HIGH 8.5
- TI-2026-28364 nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding CVSS 3.1MEDIUM 6.5
- TI-2026-28363 nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames CVSS 3.1MEDIUM 6.5
Sources
- CVE-2021-32862 · CVE Program
- CVE-2021-32862 · NVD
- FIRST EPSS
- GHSA-9jmq-rx5f-8jwq · GitHub Advisory Database · CC BY 4.0
- CVE-2021-32862 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences