{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-109740", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-10-13T00:29:46.134Z", "datePublished": "2026-10-13T12:29:26.143Z", "dateUpdated": "2026-10-13T18:17:03.396Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.5", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "158", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.5", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "158", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "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.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "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."}]}], "title": "Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2057113"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-106/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-108/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-109/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-110/"}], "credits": [{"lang": "en", "value": "Mozilla"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-10-13T18:17:03.396Z"}}}}

{}

{"affected": [{"affectedData": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.5", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "158", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.5", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "158", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-109740", "lastModified": "2026-10-13T19:18:38.053", "metrics": {}, "published": "2026-10-13T13:17:24.587", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2057113"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-106/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-108/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-109/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-110/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Deferred"}

{"bugzilla": {"description": "firefox: firefox: Sandbox escape via incorrect boundary conditions in Win32 widget", "id": "2550404", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2550404"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-653", "details": ["A flaw was found in Firefox. Incorrect boundary condition handling in the Win32 widget component allows an attacker to escape the browser's restricted sandbox environment. An attacker who has compromised a sandboxed content process could exploit this vulnerability to achieve privilege escalation and execute arbitrary code on the underlying operating system."], "name": "CVE-2026-109740", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Will not fix", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Will not fix", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Will not fix", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Will not fix", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-10-13T12:29:26Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-109740\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-109740\nhttps://bugzilla.mozilla.org/show_bug.cgi?id=2057113\nhttps://www.mozilla.org/security/advisories/mfsa2026-106/\nhttps://www.mozilla.org/security/advisories/mfsa2026-108/"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[153.5,154.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[158,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}], "created": "2026-10-13T16:30:10.406011+00:00", "updated": "2026-10-13T21:00:17.526174+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"]}