WordPress Customize Login Image plugin prior to 3.5.3 contains a cross-site scripting vulnerability via the custom logo link on the Settings page. This can allow an attacker to steal cookie-based authentication credentials and launch other attacks.
View the template here CVE-2021-33851.yaml
References:
https://cybersecurityworks.com/zerodays/cve-2021-33851-stored-cross-site-scripting-in-wordpress-customize-login-image.html