Exposure of Sensitive Information to an Unauthorized Actor
Wordpress is an open source CMS. One of the blocks in the WordPress editor can be exploited in a way that exposes password-protected posts and pages. This requires at least contributor privileges. This has been patched in WordPress 5.7.1, along with the older affected versions via minor releases. It's strongly recommended that you keep auto-updates enabled to receive the fix.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.