{"action":"Upgrade jupyter-server to 2.21.0 or later.","affected":[{"fixed":"2.21.0","introduced":"0"}],"component":"jupyter-server","cve_ids":["CVE-2026-86049"],"ecosystem":"PyPI","epss":0.00416,"exploited":false,"fixed_versions":["2.21.0"],"ghsa_id":"GHSA-c3mw-737p-c7g2","id":"tcs_01M5KH9H7V0WG543YVVV67KAKS","modified_at":"2026-10-01T17:45:05.564324201Z","published_at":"2026-10-01T16:38:33.073533Z","references":["https://osv.dev/vulnerability/PYSEC-2026-4054","https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-c3mw-737p-c7g2","https://github.com/jupyter-server/jupyter_server/pull/1681","https://github.com/jupyter-server/jupyter_server/commit/52513529af7096e622c00911b17627b266294717","https://github.com/jupyter-server/jupyter_server","https://github.com/jupyter-server/jupyter_server/releases/tag/v2.21.0","https://pypi.org/project/jupyter-server","https://github.com/advisories/GHSA-c3mw-737p-c7g2","https://nvd.nist.gov/vuln/detail/CVE-2026-86049"],"severity":{"label":"high","score":7.1},"sources":[{"source":"osv","source_id":"PYSEC-2026-4054","url":"https://osv.dev/vulnerability/PYSEC-2026-4054"}],"summary":"Jupyter Server: 5xx request logging leaks token-bearing Referer header values"}