{"@context":"https://openvex.dev/ns/v0.2.0","@id":"https://database.harborguard.co/cve/CVE-2026-44727/vex.json","author":"HarborGuard Database","role":"Document Creator","timestamp":"2026-06-22T19:56:56.776Z","version":1,"tooling":"HarborGuard Database (https://database.harborguard.co)","statements":[{"vulnerability":{"name":"CVE-2026-44727","@id":"https://www.cve.org/CVERecord?id=CVE-2026-44727","description":"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."},"products":[{"@id":"cpe:2.3:a:jupyter-server:jupyter_server:\\<_2.20:*:*:*:*:*:*:*","identifiers":{"cpe23":"cpe:2.3:a:jupyter-server:jupyter_server:\\<_2.20:*:*:*:*:*:*:*"}}],"status":"affected","action_statement":"No fixed version is published yet; monitor the upstream advisory.","timestamp":"2026-06-22T19:56:56.776Z"}]}