This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-44727 →
DEBIAN-CVE-2026-44727
Jupyter Server is the backend for Jupyter web applications. Prior to 2.20, the nbconvert HTTP handlers in jupyter_server render user-authored notebook...
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Debian:12
jupyter-server
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Debian:13
jupyter-server
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Debian:14
jupyter-server
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.20.0-1"}]}]
References
- advisory security-tracker.debian.org