CVE-2026-84128: Privilege escalation in the WebDriver BiDi component
Published Sep 1, 2026
·Updated
Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155.
Affected Software
1 affected componentFixes available
Mozilla Firefox<155
155
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 155 - Upgrade
Upgrade
Firefox WebDriver BiDito a version that resolves this vulnerability.Fixed in 155
Event History
Sep 1, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:18 PM
Data Sourced
via MITRE·12:18 PM
Description
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2026-84117
- CVE-2026-84118
- CVE-2026-84119
- CVE-2026-84120
- CVE-2026-84121
- CVE-2026-84122
- CVE-2026-84123
- CVE-2026-84124
- CVE-2026-84125
- CVE-2026-84126
- CVE-2026-84127
- CVE-2026-84128
- CVE-2026-84129
- CVE-2026-84130
- CVE-2026-84131
- CVE-2026-84132
- CVE-2026-84133
- CVE-2026-84134
- CVE-2026-84135
- CVE-2026-84136
- CVE-2026-84137
- CVE-2026-84138
- CVE-2026-84139
- CVE-2026-84140
- CVE-2026-84141
- CVE-2026-84142
- CVE-2026-84143
- CVE-2026-84144
- CVE-2026-84145
Frequently Asked Questions
1
Which Firefox versions are affected?
The issue was fixed in Firefox 155. The provided information does not specify the earliest affected version or whether any Firefox variants are affected.
2
What should teams do to remediate this issue?
Upgrade Firefox to version 155 or later, where the vulnerability is fixed. No alternative mitigation or workaround is provided in the available information.