Input validation vulnerability in Accordion 2.2.40

The Accordion plugin for WordPress is vulnerable to a type of attack called Stored Cross-Site Scripting. This attack can be carried out by people with administrative privileges on WordPress installations running versions up to 2.2.40 of the plugin. This type of attack allows malicious code to be injected into web pages. When someone accesses a web page with the malicious code, the code can be executed. This vulnerability only affects WordPress installations running on multiple sites, or sites where certain security features have been disabled.