The Freemius SDK, as used by hundreds of WordPress plugin and theme developers, was vulnerable to Cross-Site Request Forgery and Information disclosure due to missing capability checks and nonce protection on the _get_debug_log, _get_db_option, and the _set_db_option functions in versions up to, and including 2.4.2. Any WordPress plugin or theme running a version of Freemius less than 2.4.3 is vulnerable.

The Companion Sitemap Generator WordPress plugin before 4.5.3 does not sanitise and escape some parameters before outputting them back in pages, leading to Reflected Cross-Site Scripting which could be used against high privilege users such as admin.

The Companion Sitemap Generator WordPress plugin through 4.5.1.1 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.

Numerous Plugins and Themes from the AccessPress Themes (aka Access Keys) vendor are backdoored due to their website being compromised. Only plugins and themes downloaded via the vendor website are affected, and those hosted on wordpress.org are not. However, all of them were updated or removed to avoid any confusion

The companion-sitemap-generator plugin before 3.7.0 for WordPress has CSRF.