{
"id": "GHSA-5g9x-cffv-ccj8",
"aliases": [
"CVE-2026-84121"
],
"details": "Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2.",
"affected": [],
"modified": "2026-09-02T00:31:27Z",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H"
}
],
"published": "2026-09-01T15:31:07Z",
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-84121",
"type": "ADVISORY"
},
{
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2059018",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-82",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-83",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-84",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-85",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-86",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-87",
"type": "WEB"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-88",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"severity": "CRITICAL",
"github_reviewed": false,
"nvd_published_at": "2026-09-01T13:20:05Z",
"github_reviewed_at": null
}
}