{
  "cveId": "CVE-2021-23965",
  "url": "https://patchblox.com/security/cve/CVE-2021-23965",
  "summary": "CVE-2021-23965 is fixed in 4 products on 2 platforms, first by firefox 85.0\u002Bbuild1-0ubuntu0.18.04.1, released January 25, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "Firefox ESR and 1 other: Mozilla developers reported memory safety bugs present in Firefox 84.",
  "description": "Mozilla developers reported memory safety bugs present in Firefox 84. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox \u003C 85.",
  "published": "2021-01-25T16:00:00Z",
  "severity": "Medium",
  "cvss": 8.8,
  "epss": 0.00969,
  "epssPercentile": 0.62071,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://nvd.nist.gov/vuln/detail/CVE-2021-23965",
  "fixes": [
    {
      "platform": "windows-app",
      "product": "Mozilla Firefox ESR (en-US)",
      "fixedVersion": "91.0",
      "fix": "Mozilla Firefox ESR (en-US) 91.0",
      "url": "https://patchblox.com/security/fix/windows-app/mozilla.firefox.esr-91.0",
      "released": "2021-08-04T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox 85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-85.0-build1-0ubuntu0.18.04.1",
      "released": "2021-01-25T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox 85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-85.0-build1-0ubuntu0.20.04.1",
      "released": "2021-01-25T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox-geckodriver 85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-geckodriver-85.0-build1-0ubuntu0.18.04.1",
      "released": "2021-01-25T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox-geckodriver 85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-geckodriver-85.0-build1-0ubuntu0.20.04.1",
      "released": "2021-01-25T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox-mozsymbols 85.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-mozsymbols-85.0-build1-0ubuntu0.18.04.1",
      "released": "2021-01-25T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox-mozsymbols 85.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-mozsymbols-85.0-build1-0ubuntu0.20.04.1",
      "released": "2021-01-25T16:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}