CVE-2026-84139
Medium
Description
Clickjacking issue in the DOM: Events component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
SeverityMedium
CVSS6.1
Exploit probability—
Product
Mozilla Firefox
PublishedSep 1, 2026
First seenSep 1, 2026
Weakness typeCWE-1021CWE-1021
How to fix
Update
- mozilla firefox153.2.0, 155.0.0 or later
- mozilla thunderbird153.2.0, 155.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 153.2.0, 154.0.0 ≤ v < 155.0.0 | 153.2.0, 155.0.0 |
| mozilla thunderbird | v < 153.2.0, 154.0 ≤ v < 155.0 | 153.2.0, 155.0 |
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