{"id":"CVE-2026-109740","published":"2026-10-13T13:17:24Z","modified":"2026-10-19T12:16:59Z","title":"Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component","vendor":"Mozilla","product":"Firefox","tier":"core","eol":null,"description":{"text":"Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.","provenance":"source","from":"NVD"},"summary":{"text":"A sandbox escape in the Widget: Win32 component of Mozilla Firefox, caused by incorrect boundary conditions, which is classed as an improper restriction of operations within the bounds of a memory buffer. An attacker who can get a user to interact with crafted content over the network, without needing any privileges, can break out of the browser sandbox and act with greater reach on the host system.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:20:14Z"},"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":"NVD"},"epss":{"score":0.00349,"percentile":0.28599,"date":"2026-10-31","provenance":"source"},"kev":null,"vulncheckKev":null,"exploited":false,"otx":null,"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=2057113","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-109/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-110/","tags":[]}],"techniques":[],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-98502","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-98502","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[],"timeline":[{"date":"2026-10-13","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109740","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":null},"priority":{"score":12.4,"factors":[{"name":"In a KEV catalog","points":0.0,"detail":"not listed"},{"name":"Recent KEV listing","points":0.0,"detail":"not listed"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":5.72,"detail":"percentile 0.2860"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":0.0,"detail":"0 pulses"},{"name":"CVSS severity","points":6.72,"detail":"base score 9.6"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}