CVE-2023-6873: Debian Linux

High severity, CVSS 8.8. EPSS: 0.9% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 120. 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 affects Firefox < 121.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only; version 12.0 only
• Mozilla Firefox: before 121.0 (fixed in 121.0)

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