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.
History

Tue, 20 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 19 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

cvssV3_1

{'score': 9.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H'}


Wed, 14 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-653
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

threat_severity

Important


Tue, 13 Oct 2026 21:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119

Tue, 13 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5. 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.
References

Tue, 13 Oct 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Weaknesses CWE-119
Vendors & Products Mozilla
Mozilla firefox

Tue, 13 Oct 2026 13:00:00 +0000

Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5.
Title Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-10-13T12:29:26.143Z

Updated: 2026-10-19T11:52:04.550Z

Reserved: 2026-10-13T00:29:46.134Z

Link: CVE-2026-109740

cve-icon Vulnrichment

Updated: 2026-10-19T11:50:26.638Z

cve-icon NVD

Status : Deferred

Published: 2026-10-13T13:17:24.587

Modified: 2026-10-19T12:16:59.840

Link: CVE-2026-109740

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-13T12:29:26Z

Links: CVE-2026-109740 - Bugzilla