CVE-2026-86731

Craft CMS versions 5.0.0-RC1 through 5.10.11 are missing an admin-target guard in UsersController::actionActivateUser (the users/activate-user action). While the action requires the administrateUsers permission, it does not call requireAdmin() when the targeted user is an administrator, unlike the mirror action actionDeactivateUser. As a result, an authenticated control panel user who is not an administrator but holds the administrateUsers permission can activate a pending or deliberately deactivated administrator account, which can lead to permission escalation when combined with resetting that account's password. The issue is fixed in Craft CMS 5.10.12.

• https://github.com/craftcms/cms/security/advisories/GHSA-jqf5-vfg6-8cx5
• https://www.vulncheck.com/advisories/craft-cms-5.0.0-rc1-before-5.10.12-permission-escalation-via-userscontroller