CVE-2026-109720
High
Description
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
SeverityHigh
CVSS7.1
Exploit probability—
Product
Firefox
PublishedOct 13, 2026
First seenOct 13, 2026
Weakness typeCWE-843CWE-843
How to fix
Update
- Mozilla Firefox158 or later
- Mozilla Firefox ESR153.5 or later
- Mozilla Thunderbird158, 153.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Mozilla Firefox | No range specified | 158 |
| Mozilla Firefox ESR | No range specified | 153.5 |
| Mozilla Thunderbird | No range specified | 158, 153.5 |
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