The RSS Feed Widget WordPress plugin before 3.0.0 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.

The RSS Feed Widget WordPress plugin before 3.0.1 does not escape the $_SERVER['REQUEST_URI'] parameter before outputting it back in an attribute, which could lead to Reflected Cross-Site Scripting in old web browsers

The RSS Feed Widget plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's rfw-youtube-videos shortcode in all versions up to, and including, 2.9.9 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Fahad Mahmood RSS Feed Widget allows Stored XSS.This issue affects RSS Feed Widget: from n/a through 2.9.7.

Fahad Mahmood RSS Feed Widget Plugin v2.7.9 and lower does not sanitize the value of the "t" GET parameter before echoing it back out inside an input tag. This results in a reflected XSS vulnerability that attackers can exploit with a specially crafted URL.