Description
WordPress is prone to multiple prototype pollution vulnerabilities. Exploiting these issues could allow an attacker to inject key/value �properties� into JavaScript objects, potentially allowing for execution of arbitrary JavaScript in a user�s session if they can trick that user into clicking a link. WordPress versions 5.8.x ranging from 5.8 and up to (and including) 5.8.3 are vulnerable.
Remediation
Update to WordPress version 5.8.4 or latest
References
https://github.com/BlackFan/client-side-prototype-pollution/blob/master/pp/jquery-query-object.md
https://github.com/WordPress/gutenberg/pull/39365/files
https://wordpress.org/support/wordpress-version/version-5-8-4/