CVE-2024-9398EPSS p45.3%
CVE-2024-9398CVE-2024-9398
mozilla / firefox
Description
By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.
Scoring
| CVSS | 5.3 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| EPSS | 0.57% probability of exploitation · percentile 45.3% · 2026-10-10T12:00:23Z |
| Last modified | 2026-10-08 |