{"api_version":"1","generated_at":"2026-05-06T09:55:19+00:00","cve":"CVE-2026-40110","urls":{"html":"https://cve.report/CVE-2026-40110","api":"https://cve.report/api/cve/CVE-2026-40110.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-40110","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-40110"},"summary":{"title":"jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat","description":"Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). 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