5.4
Medium
CVE-2026-109721 Incorrect boundary conditions in the JavaScript Engine: JIT component
Description
Incorrect boundary conditions in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 158 | earliest → < 158 | 158 |
| Firefox 153.5 | earliest → < 153.5 | 153.5 |
| Thunderbird 158 | earliest → < 158 | 158 |
| Thunderbird 153.5 | earliest → < 153.5 | 153.5 |