CVE-2025-9187
Critical
Description
Memory safety bugs present in Firefox 141 and Thunderbird 141. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 142 and Thunderbird 142.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Mozilla Firefox
PublishedAug 19, 2025
First seenAug 19, 2025
Weakness typeCWE-119Memory buffer bounds error
How to fix
Update
- mozilla firefox142.0 or later
- mozilla thunderbird142.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 142.0 | 142.0 |
| mozilla thunderbird | v < 142.0 | 142.0 |
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