changelog: add notes about closing #11813

[skip ci]

CHANGELOG.md

@@ -10,6 +10,7 @@
 * **Discord**: Alert notification channel type for Discord, [#7964](https://github.com/grafana/grafana/issues/7964) thx [@jereksel](https://github.com/jereksel),
 * **InfluxDB**: Support SELECT queries in templating query, [#5013](https://github.com/grafana/grafana/issues/5013)
 * **Dashboard**: JSON Model under dashboard settings can now be updated & changes saved, [#1429](https://github.com/grafana/grafana/issues/1429), thx [@jereksel](https://github.com/jereksel)
+* **Security**: Fix XSS vulnerabilities in dashboard links [#11813](https://github.com/grafana/grafana/pull/11813)
 
 # 5.1.1 (2018-05-07)