CVE-2026-109763

Mitigation bypass in the File Handling component

Published Oct 13, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4836-1 firefox-esr security update
Debian DLA Debian DLA DLA-4863-1 thunderbird security update
Debian DSA Debian DSA DSA-6560-1 firefox-esr security update
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Weaknesses CWE-264
Type Values Removed Values Added
Weaknesses CWE-20
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'}

Type Values Removed Values Added
Weaknesses CWE-264
Type Values Removed Values Added
Weaknesses CWE-285
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Mozilla thunderbird
Vendors & Products Mozilla
Mozilla firefox
Mozilla thunderbird
Type Values Removed Values Added
Description Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5. Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
References
Type Values Removed Values Added
Weaknesses CWE-285
Type Values Removed Values Added
Description Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5.
Title Mitigation bypass in the File Handling component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Oct 30, 2026, 8:01 PM
Reserved
Oct 13, 2026, 12:48 AM
Status
Deferred
Published
Oct 13, 2026, 1:17 PM
Modified
Oct 30, 2026, 8:16 PM