Added MESOS-9609 to the 1.8.2 CHANGELOG.
diff --git a/CHANGELOG b/CHANGELOG
index f336fc9..dd51488 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -500,6 +500,7 @@
 * This is a bug fix release.
 
 ** Bug
+  * [MESOS-9609] - Master check failure when marking agent unreachable.
   * [MESOS-9785] - Frameworks recovered from reregistered agents are not reported to master `/api/v1` subscribers.
   * [MESOS-9836] - Docker containerizer overwrites `/mesos/slave` cgroups.
   * [MESOS-9868] - NetworkInfo from the agent /state endpoint is not correct.