CVE-2026-44727
Full vulnerability record from the local CVENow database.
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.
Severity
CRITICAL
CVSS score
9.3
(v4.0)
Vulnerability status
Modified
Source identifier
Published
2026-06-22 21:16:24.260000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
"id": "CVE-2026-44727",
"sourceIdentifier": "[email protected]",
"published": "2026-06-22T21:16:24.260",
"lastModified": "2026-10-25T23:10:00.167",
"vulnStatus": "Modified",
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"value": "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."
},
{
"lang": "es",
"value": "Jupyter Server es el backend para las aplicaciones web de Jupyter. Antes de 2.20, los manejadores HTTP de nbconvert en jupyter_server renderizan HTML de cuadernos creados por el usuario bajo el origen de Jupyter sin una directiva sandbox en su Content-Security-Policy. Combinado con el comportamiento predeterminado de no saneamiento de nbconvert.HTMLExporter, un cuaderno que lleva una carga útil HTML en una salida display_data desencadena XSS almacenado con acceso a cookies, autoridad completa sobre /api/* y RCE del kernel. Esta vulnerabilidad está corregida en 2.20."
}
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