CVE-2026-100769
High
Description
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
SeverityHigh
CVSS8.8
Exploit probability25. percentile0.3%
Product
Mozilla Firefox
PublishedSep 29, 2026
First seenSep 29, 2026
Weakness typeCWE-416Use after free
How to fix
Update
- mozilla firefox140.17.0, 153.4.0, 157.0.0 or later
- mozilla thunderbird140.17.0, 153.4.0, 157.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | 140.0.0 ≤ v < 140.17.0, 153.0.0 ≤ v < 153.4.0, 154.0.0 ≤ v < 157.0.0 | 140.17.0, 153.4.0, 157.0.0 |
| mozilla thunderbird | 140.0 ≤ v < 140.17.0, 153.0 ≤ v < 153.4.0, 154.0 ≤ v < 157.0 | 140.17.0, 153.4.0, 157.0 |
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