The Social Share Buttons plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'form (containing share_url)' parameter in all versions up to, and including, 1.30 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires that the 7-day review-nag timer has elapsed since the attacker's first wp-admin visit, as the nonce needed to reach the save-network handler is only rendered in the DOM once that timer has passed.