Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its image upload functionality. An authenticated attacker with content upload privileges (such as Author, Editor, or Administrator) can upload an SVG file containing a malicious payload, which is executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication.
The vendor was notified early about this vulnerability, but stopped responding in the middle of coordination. All versions up to 3.18.2 are considered to be vulnerable, future versions might also be vulnerable.