CVE-2026-84128
High
Description
Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
SeverityHigh
CVSS8.8
Exploit probability—
Product
Mozilla Firefox
PublishedSep 1, 2026
First seenSep 1, 2026
Weakness typeCWE-284Improper access control
How to fix
Update
- mozilla firefox155.0.0 or later
- mozilla thunderbird155.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 155.0.0 | 155.0.0 |
| mozilla thunderbird | v < 155.0 | 155.0 |
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