CVE-2026-7321
Critical
Description
Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, and Thunderbird 140.10.1.
SeverityCritical
CVSS9.6
Exploit probability—
Product
Mozilla Firefox
PublishedApr 28, 2026
First seenApr 28, 2026
Weakness typeCWE-120CWE-120
How to fix
Update
- mozilla firefox140.10.1, 150.0 or later
- mozilla thunderbird140.10.1, 150.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 140.10.1, v < 150.0 | 140.10.1, 150.0 |
| mozilla thunderbird | v < 140.10.1, v < 150.0 | 140.10.1, 150.0 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.