Ghost versions from 0.5.3 through versions prior to 6.50.0 fail to sanitize the data placed in...

Ghost versions from 0.5.3 through versions prior to 6.50.0 fail to sanitize the data placed in the JSON-LD HTML tag emitted by the {{ghost_head}} helper. An authenticated user with limited privileges can inject unescaped content that is rendered as script in the published page, potentially leading to compromise of a staff user's admin session when that user views the affected page.