The Translate Multilingual sites WordPress plugin before 2.3.3 is vulnerable to an authenticated SQL injection. By adding a new language (via the settings page) containing specific special characters, the backticks in the SQL query can be surpassed and a time-based blind payload can be injected.
The TranslatePress WordPress plugin before 2.0.9 does not implement a proper sanitisation on the translated strings. The 'trp_sanitize_string' function only removes script tag with a regex, still allowing other HTML tags and attributes to execute javascript, which could lead to authenticated Stored Cross-Site Scripting issues.