CVE-2026-100794

Sandbox escape due to incorrect boundary conditions in the Internationalization component

Published Sep 29, 2026 CVSS 3.1 · 9.6 Critical EPSS < 1% KEV · Not listed
Description
Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4810-1 thunderbird security update
Debian DLA Debian DLA DLA-4814-1 firefox-esr security update
Debian DSA Debian DSA DSA-6533-1 firefox-esr security update
Debian DSA Debian DSA DSA-6536-1 thunderbird security update
History
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Weaknesses CWE-120
CWE-20
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Weaknesses CWE-119
Metrics 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'}

Type Values Removed Values Added
Weaknesses CWE-120
CWE-20
Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Firefox 157, and Firefox ESR 140.17. Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
References
Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17. Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Firefox 157, and Firefox ESR 140.17.
References
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Weaknesses CWE-20
Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17.
Title Sandbox escape due to incorrect boundary conditions in the Internationalization component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Oct 1, 2026, 2:55 PM
Reserved
Sep 26, 2026, 7:17 PM
Status
Analyzed
Published
Sep 29, 2026, 1:17 PM
Modified
Oct 19, 2026, 3:26 PM