CVE-2023-4054: Mozilla Firefox

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

When opening appref-ms files, Firefox did not warn the user that these files may contain malicious code. *This bug only affects Firefox on Windows. Other operating systems are unaffected.* This vulnerability affects Firefox < 116, Firefox ESR < 102.14, Firefox ESR < 115.1, Thunderbird < 102.14, and Thunderbird < 115.1.

Affected products

• Mozilla Firefox: before 116.0 (fixed in 116.0); from 102.0, before 102.14 (fixed in 102.14); from 115.0, before 115.1 (fixed in 115.1)

Published 2023-08-01. Last modified 2026-06-17.