CVE-2026-16388

Sandbox escape in the DOM: Networking component

Published Jul 21, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153. Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
References
Type Values Removed Values Added
Weaknesses CWE-693
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Description Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153.
Title Sandbox escape in the DOM: Networking component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Jul 22, 2026, 7:18 PM
Reserved
Jul 20, 2026, 9:57 PM
Status
Analyzed
Published
Jul 21, 2026, 1:17 PM
Modified
Oct 24, 2026, 8:10 PM
Severity
Moderate
Public date
Jul 21, 2026, 12:38 PM