The JetEngine WordPress plugin before 3.8.14 adds SVG to the site-wide list of allowed upload types without sanitising the file contents, allowing users with the upload files capability, such as Authors, to upload a file containing malicious JavaScript that executes in the browser of any user who opens it (Stored Cross-Site Scripting). On multisite, this also overrides an upload-type restriction set by the network administrator.
Analyzing vulnerability vectors…