CVE-2026-84128
HIGH severity · CVSS 8.8 · Improper access control
8.8CVSS HIGH
Summary
Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products we track (2)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.