{"action":"Upgrade jupyter-server to 2.20.0 or later.","affected":[{"fixed":"2.20.0","introduced":"0"}],"component":"jupyter-server","cve_ids":["CVE-2026-44727"],"ecosystem":"PyPI","epss":0.00438,"exploited":false,"fixed_versions":["2.20.0"],"ghsa_id":"GHSA-fcw5-x6j4-ccmp","id":"tcs_01M5KFF2HQ9BG3WY5M1XQ73W0M","modified_at":"2026-09-10T03:50:49.418798509Z","published_at":"2026-06-18T15:04:07Z","references":["https://osv.dev/vulnerability/GHSA-fcw5-x6j4-ccmp","https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-fcw5-x6j4-ccmp","https://nvd.nist.gov/vuln/detail/CVE-2026-44727","https://github.com/jupyter-server/jupyter_server/commit/6cbee8d65e71abac851c4492fea987ad080580bd","https://access.redhat.com/errata/RHSA-2026:43038","https://access.redhat.com/errata/RHSA-2026:60520","https://access.redhat.com/security/cve/CVE-2026-44727","https://bugzilla.redhat.com/show_bug.cgi?id=2491516","https://github.com/advisories/GHSA-fcw5-x6j4-ccmp","https://github.com/jupyter-server/jupyter_server","https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2026-366.yaml","https://pypi.org/project/jupyter-server","https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44727.json"],"severity":{"label":"medium","score":5.4},"sources":[{"source":"osv","source_id":"GHSA-fcw5-x6j4-ccmp","url":"https://osv.dev/vulnerability/GHSA-fcw5-x6j4-ccmp"}],"summary":"Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP"}