{"id":"CVE-2026-100819","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100819","generatedAt":"2026-10-28T01:01:19.473Z","title":"This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.","description":"Sandbox escape due to incorrect boundary conditions in the XPCOM component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.","published":"2026-09-29T13:17:47.000Z","lastModified":"2026-10-05T14:07:09.000Z","status":"Analyzed","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":9.6,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H"},"cwe":["CWE-119"],"affected":["mozilla/firefox","mozilla/thunderbird"],"epss":{"score":0.00264,"percentile":0.18148,"date":"2026-10-26","history":[{"date":"2026-09-30","score":0.00255,"percentile":0.15459}]},"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 (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-09-29T15:45:16.000Z","detail":{"from":null,"score":"9.6","severity":"CRITICAL","fromSeverity":null},"summary":"Now scored CVSS 9.6 CRITICAL."},{"kind":"new","label":"New CVE","at":"2026-09-29T13:17:47.000Z","detail":{"score":null,"severity":null,"publishedAt":"2026-09-29T13:17:47.193Z"},"summary":"New CVE, critical severity (CVSS 9.6)."}],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2071069","tags":["Permissions Required"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-100/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-101/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-102/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-103/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-97/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-98/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-99/","tags":["Vendor Advisory"],"source":"security@mozilla.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100819","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."}