Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
From USN-5475-1:
Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, spoof the browser UI, conduct cross-site scripting (XSS) attacks, bypass content security policy (CSP) restrictions, or execute arbitrary code.
With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.
– Scott Cheney, Manager of Information Security, Sierra View Medical Center