Fix: prevent user serialization for SocialActivity

protected/humhub/components/SocialActivity.php

@@ -374,7 +374,7 @@ abstract class SocialActivity extends \yii\base\BaseObject implements rendering\
     {
         return serialize([
             'source' => $this->source,
-            'originator' => $this->originator
+            'originator_id' => $this->originator->id
         ]);
     }
 
@@ -389,7 +389,7 @@ abstract class SocialActivity extends \yii\base\BaseObject implements rendering\
     {
         $this->init();
         $unserializedArr = unserialize($serialized);
-        $this->from($unserializedArr['originator']);
+        $this->from(User::findOne(['id' => $unserializedArr['originator_id']]));
         $this->about($unserializedArr['source']);
     }
 }

protected/humhub/docs/CHANGELOG.md

@@ -1,6 +1,10 @@
 HumHub Change Log
 =================
 
+1.3.0-beta.3
+-----------------------------
+
+- Fix: prevent user serialization for SocialActivity
 
 1.3.0-beta.2  (July 18, 2018)
 -----------------------------
@@ -50,6 +54,7 @@ Please read the [Update Guide](http://docs.humhub.org/beta/admin-updating-130.ht
 - Enh: Removed built and compressed assets from GitHub sources
 
 
+
 1.3.0-beta.1  (July 4, 2018)
 ----------------------------