CVE-2026-8962
High
Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
SeverityHigh
CVSS8.1
Exploit probability31. percentile0.4%
Product
Mozilla Firefox
PublishedMay 19, 2026
First seenMay 19, 2026
Weakness typeCWE-693CWE-693
How to fix
Update
- mozilla firefox140.11.0, 151.0.0 or later
- mozilla thunderbird140.11, 151.0.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 140.11.0, v < 151.0.0 | 140.11.0, 151.0.0 |
| mozilla thunderbird | v < 140.11, v < 151.0.0 | 140.11, 151.0.0 |
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