Jetpack < 13.8 is vulnerable to Contributor+ Stored XSS vulnerability

The Jetpack plugin for WordPress, versions less than and equal to 13.7, and the Jetpack Boost plugin for WordPress, versions less than and equal to 3.4.7, are vulnerable to Stored Cross-Site Scripting via the Site Accelerator feature due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.