A website was able to detect when a user took a screenshot of a page using the built-in Screenshot functionality in Firefox. This vulnerability affects Firefox < 127.
Severity
CVSS 3.1
4.3 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS
0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-31)