is_blog_installed in wp-includes/functions.php in WordPress before 5.5.2 improperly determines whether WordPress is already installed, which might allow an attacker to perform a new installation, leading to remote code execution (as well as a denial of service for the old installation).
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
8.1% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-31)