{
  "cveId": "CVE-2017-7820",
  "url": "https://patchblox.com/security/cve/CVE-2017-7820",
  "summary": "CVE-2017-7820 is fixed in 4 products on 1 platform, first by firefox 56.0\u002Bbuild6-0ubuntu1, released October 1, 2017. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "firefox: The \u0022instanceof\u0022 operator can bypass the Xray wrapper mechanism",
  "description": "The \u0022instanceof\u0022 operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox \u0026lt; 56.",
  "published": "2017-10-01T17:00:00Z",
  "severity": "Low",
  "epss": 0.01163,
  "epssPercentile": 0.67393,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "56.0\u002Bbuild6-0ubuntu1",
      "fix": "firefox 56.0\u002Bbuild6-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-56.0-build6-0ubuntu1",
      "released": "2017-10-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-globalmenu",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "56.0\u002Bbuild6-0ubuntu1",
      "fix": "firefox-globalmenu 56.0\u002Bbuild6-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-globalmenu-56.0-build6-0ubuntu1",
      "released": "2017-10-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "56.0\u002Bbuild6-0ubuntu1",
      "fix": "firefox-mozsymbols 56.0\u002Bbuild6-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-mozsymbols-56.0-build6-0ubuntu1",
      "released": "2017-10-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-testsuite",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "56.0\u002Bbuild6-0ubuntu1",
      "fix": "firefox-testsuite 56.0\u002Bbuild6-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-testsuite-56.0-build6-0ubuntu1",
      "released": "2017-10-01T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-07T12:40:37Z"
}