diff --git a/debian/changelog b/debian/changelog
index 300f8c1..df3c128 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,6 @@
 cm4all-lukko (0.30) unstable; urgency=low
 
-  * 
+  * use open(O_NONBLOCK) to fix FIFO DoS vulnerability
 
  --   
 
diff --git a/libcommon b/libcommon
index c945716..63c9f01 160000
--- a/libcommon
+++ b/libcommon
@@ -1 +1 @@
-Subproject commit c9457164dba42afd069cd18dfbbc927473ce7469
+Subproject commit 63c9f01d507e99b39bf663302de103e508fb3b78