There are very helpful visual studio extensions available. Are there any security issue or vulnerabilities by adding or using them into visual studio? I am using visual studio 2015. if threats will be there, then provide some suggestions.
Add the solution:
(1)If you want to use the extension tool of the marketplace site. I didn't find any security issue for it, I often use some of them, they are safe.
Since marketplace site would have its own requirements, in addition, the community members could report this issue to the extension tool under Q & A or other ways even if it has certain limitations more or less, So the code author could update it in time. SO I think the extension tools are safe.
(2)If you want to write custom extension, it also has the best practices for Security:
https://msdn.microsoft.com/en-us/library/bb166442.aspx
Of course, if you find any safe or other issues for any extension tools from the marketplace, you could ask the issue here, I will help you repro this issue using the same Environment as yours.