Spiffy Calendar < 4.9.6 - Authenticated (Contributor+) Stored Cross-Site Scripting

Description The Spiffy Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin’s shortcode(s) in all versions up to 4.9.6 (exclusive) 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.