{
  "cveId": "CVE-2021-29961",
  "url": "https://patchblox.com/security/cve/CVE-2021-29961",
  "summary": "CVE-2021-29961 is fixed in 4 products on 2 platforms, first by firefox 89.0\u002Bbuild2-0ubuntu0.18.04.2, released June 1, 2021. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "Mozilla Firefox ESR: When styling and rendering an oversized \u0060\u003Cselect\u003E\u0060 element, Firefox did not apply correct clipping which\u2026",
  "description": "When styling and rendering an oversized \u0060\u003Cselect\u003E\u0060 element, Firefox did not apply correct clipping which allowed an attacker to paint over the user interface. This vulnerability affects Firefox \u003C 89.",
  "published": "2021-06-01T17:00:00Z",
  "severity": "Medium",
  "cvss": 4.3,
  "epss": 0.0076,
  "epssPercentile": 0.5556,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://nvd.nist.gov/vuln/detail/CVE-2021-29961",
  "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": "89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "fix": "firefox 89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-89.0-build2-0ubuntu0.18.04.2",
      "released": "2021-06-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "fix": "firefox 89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-89.0-build2-0ubuntu0.20.04.2",
      "released": "2021-06-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "fix": "firefox-geckodriver 89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-geckodriver-89.0-build2-0ubuntu0.18.04.2",
      "released": "2021-06-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "fix": "firefox-geckodriver 89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-geckodriver-89.0-build2-0ubuntu0.20.04.2",
      "released": "2021-06-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "fix": "firefox-mozsymbols 89.0\u002Bbuild2-0ubuntu0.18.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-mozsymbols-89.0-build2-0ubuntu0.18.04.2",
      "released": "2021-06-01T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "fix": "firefox-mozsymbols 89.0\u002Bbuild2-0ubuntu0.20.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-mozsymbols-89.0-build2-0ubuntu0.20.04.2",
      "released": "2021-06-01T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-10T13:56:55Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}