CVE-2026-16360
Critical
Description
Memory safety bugs present in Thunderbird ESR 140.12 and Thunderbird 152. 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 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Mozilla Firefox
PublishedJul 21, 2026
First seenJul 21, 2026
Weakness typeCWE-119Memory buffer bounds error
How to fix
Update
- mozilla firefox115.38.0, 153.0.0, 140.13.0 or later
- mozilla thunderbird140.13.0, 153.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 115.38.0, v < 153.0.0, 128.1.0 ≤ v < 140.13.0 | 115.38.0, 153.0.0, 140.13.0 |
| mozilla thunderbird | v < 140.13.0, 141.0 ≤ v < 153.0 | 140.13.0, 153.0 |
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