Update SECURITY.md

Closes bazelbuild#14863.

PiperOrigin-RevId: 429552204

SECURITY.md

@@ -2,9 +2,11 @@
 
 ## Reporting a Vulnerability
 
-To report a security issue, please email [email protected] with a description
-of the issue, the steps you took to create the issue, affected versions, and, if
-known, mitigations for the issue. Our vulnerability management team will respond
-within 3 working days of your email. If the issue is confirmed as a
-vulnerability, we will open a Security Advisory. This project follows a 90 day
-disclosure timeline.
+Please use https://g.co/vulnz to report security vulnerabilities.
+
+We use https://g.co/vulnz for our intake and triage. For valid issues we will do
+coordination and disclosure here on GitHub (including using a GitHub Security
+Advisory when necessary).
+
+The Google Security Team will process your report within a day, and respond
+within a week (although it will depend on the severity of your report).