CVE-2026-113399
Critical
Description
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
SeverityCritical
CVSS9.8
Exploit probability—
ProductFirefox
PublishedOct 20, 2026
First seenOct 20, 2026
Weakness typeCWE-190Integer overflow
How to fix
Update
- Firefox158.0.1 or later
- Thunderbird158.0.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox | No range specified | 158.0.1 |
| Thunderbird | No range specified | 158.0.1 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
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