diff --git a/config/software/mattermost.rb b/config/software/mattermost.rb
index d91537098cf4a5f7236b06ddac93fb2f33790986_Y29uZmlnL3NvZnR3YXJlL21hdHRlcm1vc3QucmI=..9fc28a2548a32cb9cf60ac96322bedac038993e6_Y29uZmlnL3NvZnR3YXJlL21hdHRlcm1vc3QucmI= 100644
--- a/config/software/mattermost.rb
+++ b/config/software/mattermost.rb
@@ -17,6 +17,6 @@
 #
 
 name 'mattermost'
-default_version '4.7.3'
+default_version '4.8.0'
 
 source url: "https://releases.mattermost.com/#{version}/mattermost-team-#{version}-linux-amd64.tar.gz",
@@ -21,6 +21,6 @@
 
 source url: "https://releases.mattermost.com/#{version}/mattermost-team-#{version}-linux-amd64.tar.gz",
-       md5: '1786bcb0bcc2880bd6eaabb8037f7063'
+       md5: '576247a7412b16a8c1f829e56f27c9b1'
 
 relative_path 'mattermost'
 
diff --git a/files/gitlab-config-template/gitlab.rb.template b/files/gitlab-config-template/gitlab.rb.template
index d91537098cf4a5f7236b06ddac93fb2f33790986_ZmlsZXMvZ2l0bGFiLWNvbmZpZy10ZW1wbGF0ZS9naXRsYWIucmIudGVtcGxhdGU=..9fc28a2548a32cb9cf60ac96322bedac038993e6_ZmlsZXMvZ2l0bGFiLWNvbmZpZy10ZW1wbGF0ZS9naXRsYWIucmIudGVtcGxhdGU= 100644
--- a/files/gitlab-config-template/gitlab.rb.template
+++ b/files/gitlab-config-template/gitlab.rb.template
@@ -1133,6 +1133,7 @@
 # mattermost['service_address'] = "127.0.0.1"
 # mattermost['service_port'] = "8065"
 # mattermost['service_site_url'] = nil
+# mattermost['service_websocket_url'] = nil
 # mattermost['service_maximum_login_attempts'] = 10
 # mattermost['service_google_developer_key'] = nil
 # mattermost['service_enable_incoming_webhooks'] = true
@@ -1143,6 +1144,7 @@
 # mattermost['service_enable_insecure_outgoing_connections'] = false
 # mattermost['service_allowed_untrusted_internal_connections'] = ""
 # mattermost['service_allow_cors_from'] = ""
+# mattermost['service_allow_cookies_from_subdomains'] = false
 # mattermost['service_enable_outgoing_webhooks'] = true
 # mattermost['service_enable_commands'] = true
 # mattermost['service_enable_custom_emoji'] = false
diff --git a/files/gitlab-cookbooks/mattermost/attributes/default.rb b/files/gitlab-cookbooks/mattermost/attributes/default.rb
index d91537098cf4a5f7236b06ddac93fb2f33790986_ZmlsZXMvZ2l0bGFiLWNvb2tib29rcy9tYXR0ZXJtb3N0L2F0dHJpYnV0ZXMvZGVmYXVsdC5yYg==..9fc28a2548a32cb9cf60ac96322bedac038993e6_ZmlsZXMvZ2l0bGFiLWNvb2tib29rcy9tYXR0ZXJtb3N0L2F0dHJpYnV0ZXMvZGVmYXVsdC5yYg== 100644
--- a/files/gitlab-cookbooks/mattermost/attributes/default.rb
+++ b/files/gitlab-cookbooks/mattermost/attributes/default.rb
@@ -37,6 +37,7 @@
 default['mattermost']['service_port'] = "8065"
 
 default['mattermost']['service_site_url'] = nil
+default['mattermost']['service_websocket_url'] = nil
 default['mattermost']['service_maximum_login_attempts'] = 10
 default['mattermost']['service_google_developer_key'] = nil
 default['mattermost']['service_enable_incoming_webhooks'] = false
@@ -47,6 +48,7 @@
 default['mattermost']['service_enable_insecure_outgoing_connections'] = false
 default['mattermost']['service_allowed_untrusted_internal_connections'] = nil
 default['mattermost']['service_allow_cors_from'] = nil
+default['mattermost']['service_allow_cookies_from_subdomains'] = false
 default['mattermost']['service_enable_outgoing_webhooks'] = false
 default['mattermost']['service_enable_commands'] = true
 default['mattermost']['service_enable_custom_emoji'] = false
diff --git a/files/gitlab-cookbooks/mattermost/templates/default/config.json.erb b/files/gitlab-cookbooks/mattermost/templates/default/config.json.erb
index d91537098cf4a5f7236b06ddac93fb2f33790986_ZmlsZXMvZ2l0bGFiLWNvb2tib29rcy9tYXR0ZXJtb3N0L3RlbXBsYXRlcy9kZWZhdWx0L2NvbmZpZy5qc29uLmVyYg==..9fc28a2548a32cb9cf60ac96322bedac038993e6_ZmlsZXMvZ2l0bGFiLWNvb2tib29rcy9tYXR0ZXJtb3N0L3RlbXBsYXRlcy9kZWZhdWx0L2NvbmZpZy5qc29uLmVyYg== 100644
--- a/files/gitlab-cookbooks/mattermost/templates/default/config.json.erb
+++ b/files/gitlab-cookbooks/mattermost/templates/default/config.json.erb
@@ -1,6 +1,7 @@
 {
     "ServiceSettings": {
         "SiteURL": "<%= @service_site_url %>",
+        "WebsocketURL": "<%= @service_websocket_url %>",
         "ListenAddress": "<%= @service_address %>:<%= @service_port %>",
         "ConnectionSecurity": "<%= @service_connection_security %>",
         "TLSCertFile": "<%= @service_tls_cert_file %>",
@@ -25,6 +26,7 @@
         "EnableInsecureOutgoingConnections":  <%= @service_enable_insecure_outgoing_connections %>,
         "AllowedUntrustedInternalConnections":  "<%= @service_allowed_untrusted_internal_connections %>",
         "AllowCorsFrom":  "<%= @service_allow_cors_from %>",
+        "AllowCookiesForSubdomains": <%= @service_allow_cookies_from_subdomains %>,
         "EnableDeveloper": <%= @service_enable_developer %>,
         "SessionLengthWebInDays" : <%= @service_session_length_web_in_days %>,
         "SessionLengthMobileInDays" : <%= @service_session_length_mobile_in_days %>,