{"id":"CVE-2026-100819","published":"2026-09-29T12:36:29Z","modified":"2026-09-30T17:20:47Z","title":"Sandbox escape due to incorrect boundary conditions in the XPCOM component","vendor":"Mozilla","product":"Firefox","tier":"tail","description":{"text":"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.","provenance":"source","from":"CVE.org"},"cvss":{"score":9.6,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","provenance":"source","from":"CISA ADP Vulnrichment"},"epss":{"score":0.00264,"percentile":0.18317,"provenance":"source"},"cwes":[{"id":"CWE-119","name":"Improper Restriction of Operations within the Bounds of a Memory Buffer"}],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2071069","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-100/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-101/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-102/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-103/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-97/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-98/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-99/","tags":[]}],"priority":{"score":10.4,"factors":[{"name":"EPSS percentile","points":3.66},{"name":"CVSS severity","points":6.72}]},"vendorSlug":"mozilla","euvd":{"id":"EUVD-2026-88798","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-class-mozilla-firefox-cwe-119"}}