Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP
28Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 9.3epss 0.3%
probabilidad de explotación
0.3%top 77% de las CVE
explotación observada
noninguna fuente lo reporta
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Productos afectados
jupyter-server · jupyter_serverReferencias
https://access.redhat.com/errata/RHSA-2026:43038https://access.redhat.com/security/cve/CVE-2026-44727https://bugzilla.redhat.com/show_bug.cgi?id=2491516https://github.com/jupyter-server/jupyter_server/commit/6cbee8d65e71abac851c4492fea987ad080580bdhttps://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-fcw5-x6j4-ccmphttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44727.json