Medium (6.1) in mozilla firefox. EPSS 0.6% chance of exploitation in the next 30 days.
The default webcal: protocol handler will load a web site vulnerable to cross-site scripting (XSS) attacks. This default was left in place as a legacy feature and has now been removed. *Note: this issue only affects users with an account on the vulnerable service. Other users are unaffected.*. This vulnerability affects Firefox < 67.
Severity
CVSS 3.0
6.1 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-31)