{"id":"CVE-2026-16387","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-16387","generatedAt":"2026-10-27T23:10:18.625Z","title":"This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.","description":"Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.","published":"2026-07-21T13:17:14.000Z","lastModified":"2026-10-24T20:10:00.000Z","status":"Analyzed","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-200","CWE-284","CWE-346"],"affected":["mozilla/firefox","mozilla/thunderbird"],"epss":{"score":0.00284,"percentile":0.20728,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2043200","tags":["Permissions Required"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-68/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-70/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-71/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-72/","tags":["Vendor Advisory"],"source":"security@mozilla.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-16387","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}