{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:jupyter:jupyter_server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.18.0"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0ceed45a803ca36735f0fcfeb6d9db9430a50aa0"
            },
            {
              "fixed": "057869a327c46730afede3eab0ca2d2e3e74acea"
            },
            {
              "fixed": "49b34392feaa97735b3b777e3baf8f22f2a14ed8"
            }
          ],
          "repo": "https://github.com/jupyter-server/jupyter_server",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-24qx-w28j-9m6p"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-777"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40110.json"
  },
  "details": "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). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.",
  "id": "CVE-2026-40110",
  "modified": "2026-07-15T01:49:08.249487958Z",
  "published": "2026-05-05T21:29:31.323Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40110.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-40110"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40110.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40110"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2466912"
    },
    {
      "type": "FIX",
      "url": "https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea"
    },
    {
      "type": "FIX",
      "url": "https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8"
    },
    {
      "type": "FIX",
      "url": "https://github.com/jupyter-server/jupyter_server/pull/603"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat"
}