8.8
High
CVE-2026-74939 Privilege escalation in the DOM: Navigation component
Description
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 154 | earliest → < 154 | 154 |
| Firefox 153.1 | earliest → < 153.1 | 153.1 |
| Firefox 140.14 | earliest → < 140.14 | 140.14 |
| Firefox 115.39 | earliest → < 115.39 | 115.39 |
| Thunderbird 154 | earliest → < 154 | 154 |
| Thunderbird 153.1 | earliest → < 153.1 | 153.1 |
| Thunderbird 140.14 | earliest → < 140.14 | 140.14 |