9.8
Critical
CVE-2025-1020 Memory safety bugs present in Firefox 134 and Thunderbird 134
Description
Memory safety bugs present in Firefox 134 and Thunderbird 134. 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 135 and Thunderbird 135.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 135 | earliest → < 135 | 135 |
| Thunderbird 135 | earliest → < 135 | 135 |
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