9.8
Critical
CVE-2025-0247 Memory safety bugs present in Firefox 133 and Thunderbird 133
Description
Memory safety bugs present in Firefox 133 and Thunderbird 133. 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 134 and Thunderbird 134.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 134 | earliest → < 134 | 134 |
| Thunderbird 134 | earliest → < 134 | 134 |
Other CVEs of Firefox
The 2221 CVEs of Firefox →
CVE-2026-120572
Incorrect boundary conditions in the Layout: Block and Inline component
8.8
High
CVE-2026-118027
Frame poisoning in the Layout component
9.1
Critical
CVE-2026-118024
Use-after-free in the Graphics: Text component
8.8
High
CVE-2026-118026
Invalid pointer in the JavaScript: GC component
8.8
High