CVE-2026-84128

Privilege escalation in the WebDriver BiDi component

Published Sep 1, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

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
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-285
Type Values Removed Values Added
Description Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155. Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
References
Type Values Removed Values Added
Weaknesses CWE-284
Metrics cvssV3_1

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

ssvc

{'options': {'Automatable': 'no', '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
Weaknesses CWE-285
Type Values Removed Values Added
Description Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155.
Title Privilege escalation in the WebDriver BiDi component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Sep 2, 2026, 3:55 AM
Reserved
Sep 1, 2026, 7:25 AM
Status
Analyzed
Published
Sep 1, 2026, 1:20 PM
Modified
Sep 3, 2026, 12:54 PM