The limit-login-attempts-reloaded plugin before 2.17.4 for WordPress allows wp-admin/options-general.php?page=limit-login-attempts&tab= XSS. A malicious user can cause an administrator user to supply dangerous content to the vulnerable page, which is then reflected back to the user and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or e-mailed directly to victims.

LimitLoginAttempts.php in the limit-login-attempts-reloaded plugin before 2.17.4 for WordPress allows a bypass of (per IP address) rate limits because the X-Forwarded-For header can be forged. When the plugin is configured to accept an arbitrary header for the client source IP address, a malicious user is not limited to perform a brute force attack, because the client IP header accepts any arbitrary string. When randomizing the header input, the login count does not ever reach the maximum allowed retries.

The Limit Login Attempts Reloaded WordPress plugin before 2.25.26 is missing authorization on the `toggle_auto_update` AJAX action, allowing any user with a valid nonce to toggle the auto-update status of the plugin.

The Limit Login Attempts Reloaded plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in all versions up to, and including, 2.25.26 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.