jupyter-server: Jupyter Server is the backend for Jupyter web applications
CVE-2026-44727 is fixed in 4 products on 1 platform, first by FEDORA-2026-275D2ECBBD, released June 26, 2026. It is not reported as exploited. Patch Radar priority: Routine.
Jupyter Server is the backend for Jupyter web applications. Prior to 2.20, the nbconvert HTTP handlers in jupyter_server render user-authored notebook HTML under the Jupyter origin without a sandbox directive in their Content-Security-Policy. Combined with nbconvert.HTMLExporter's default non-sanitizing behavior, a notebook carrying an HTML payload in a display_data output triggers stored XSS with cookie access, full /api/* authority, and kernel RCE. This vulnerability is fixed in 2.20.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| jupyter-server · Debian 14 | 2.20.0-1 | DEBIAN-CVE-2026-44727 | Jul 18, 2026 |
| python-jupyter-server · Fedora 43 | 2.20.0-1.fc43 | FEDORA-2026-275D2ECBBD | Jun 26, 2026 |
| python3-jupyter-server · Fedora 43 | 2.20.0-1.fc43 | FEDORA-2026-275D2ECBBD | Jun 26, 2026 |
| python3-jupyter-server+test · Fedora 43 | 2.20.0-1.fc43 | FEDORA-2026-275D2ECBBD | Jun 26, 2026 |
Patch Radar data is free to use with attribution. Terms and how to credit it.
Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.