Added cvss_v3 field to advisory

Author: jasnow

gems/stringio/CVE-2024-27280.yml

@@ -24,5 +24,6 @@ description: |
 
   You can use `gem update stringio` to update it. If you are using bundler,
   please add `gem "stringio", ">= 3.0.1.2"` to your `Gemfile`.
+cvss_v3: 9.8
 patched_versions:
   - ">= 3.0.1.1"