diff --git a/pom.xml b/pom.xml
old mode 100755
new mode 100644
index 8ef72a84e..08d865b14
--- a/pom.xml
+++ b/pom.xml
@@ -58,7 +58,7 @@
         <scala.version>2.11</scala.version>
         <akka.version>2.5.18</akka.version>
         <californium.version>1.0.2</californium.version>
-        <gson.version>2.6.2</gson.version>
+        <gson.version>2.8.9</gson.version>
         <velocity.version>1.7</velocity.version>
         <velocity-tools.version>2.0</velocity-tools.version>
         <mail.version>1.4.3</mail.version>