Nessus versions 7.0.3 and earlier have been found vulnerable to two separate issues.
The first vulnerability (XSS) exists due to improper input validation. An authenticated attacker could create and upload a .nessus file, that may be viewed by an administrator allowing for the execution of arbitrary script code in a user’s browser session. In other scenarios, XSS could occur by altering system variables from the Advanced Settings.
CVE-2018-1147 - CVSSv2 (AV:A/AC:H/Au:M/C:P/I:C/A:P/E:POC/RL:OF/RC:C/CDP:L/TD:L/CR:L/IR:L/AR:L)