OctavoCMS suffers from a cross site scripting vulnerability.
40555240910c0e6eb98ffb5572b318904d8558ae1acf088cd26a84512b9a1f17
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: https://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.