CVE-2023-6870: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Applications which spawn a Toast notification in a background thread may have obscured fullscreen notifications displayed by Firefox. *This issue only affects Android versions of Firefox and Firefox Focus.* This vulnerability affects Firefox < 121.

Affected products

• Mozilla Firefox: before 121.0 (fixed in 121.0)
• Mozilla Firefox Focus: affected versions not specified

Published 2023-12-19. Last modified 2026-06-17.