YCM remote code execution vulnerability

[Strahinja Markovic]

A remote code execution vulnerability has been found in YCM. It's a fairly involved and convoluted exploit, but it can be triggered by just opening a link to a malicious website.

A fix for the issue has already landed in the master branch. Update to the latest YCM to get the fix. If you installed with Vundle, you can update by running ":BundleUpdate" in Vim.

I'd like to thank Stephen Röttger for finding the issue, creating a working exploit and responsibly disclosing it. Thank you Stephen!