CVE-2024-8383: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme that the browser does not support. It did not ask before doing so for the Usenet-related schemes news: and snews:. Since most operating systems don't have a trusted newsreader installed by default, an unscrupulous program that the user downloaded could register itself as a handler. The website that served the application download could then launch that application at will. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.

Affected products

• Mozilla Firefox: before 130.0 (fixed in 130.0)
• Mozilla Firefox ESR: before 115.15 (fixed in 115.15); from 128.0, before 128.2 (fixed in 128.2)

Published 2024-09-03. Last modified 2026-06-17.