Redmine

https://docs.gravatar.com/avatars/hash/

This is extracted from #35217.

diff --git a/lib/plugins/gravatar/lib/gravatar.rb b/lib/plugins/gravatar/lib/gravatar.rb
index ea4a37cb5..4dc27db52 100644
--- a/lib/plugins/gravatar/lib/gravatar.rb
+++ b/lib/plugins/gravatar/lib/gravatar.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true

-require 'digest/md5'
 require 'cgi'

 module GravatarHelper
@@ -65,7 +64,7 @@ module GravatarHelper

     # Return the gravatar URL for the given email address.
     def gravatar_url(email, options={})
-      email_hash = Digest::MD5.hexdigest(email)
+      email_hash = Digest::SHA256.hexdigest(email)
       options = DEFAULT_OPTIONS.merge(options)
       options[:default] = CGI::escape(options[:default]) unless options[:default].nil?
       gravatar_api_url(email_hash).tap do |url|