The reCAPTCHA WordPress plugin through 1.6 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).

The Login No Captcha reCAPTCHA WordPress plugin before 1.7 doesn't check the proper IP address allowing attackers to spoof IP addresses on the allow list and bypass the need for captcha on the login screen.

An XSS issue was discovered in ReCaptcha Solver 5.7. A response from Anti-Captcha.com, RuCaptcha.com, 2captcha.com, DEATHbyCAPTCHA.com, ImageTyperz.com, or BestCaptchaSolver.com in setCaptchaCode() is inserted into the DOM as HTML, resulting in full control over the user's browser by these servers.