diff -Nru glib2.0-2.56.4/debian/changelog glib2.0-2.56.4/debian/changelog
--- glib2.0-2.56.4/debian/changelog	2019-03-22 12:17:34.000000000 +0000
+++ glib2.0-2.56.4/debian/changelog	2019-06-05 16:47:02.000000000 +0000
@@ -1,3 +1,12 @@
+glib2.0 (2.56.4-0ubuntu0.18.04.3) bionic-security; urgency=medium
+
+  * SECURITY UPDATE: Less restrictive permissions during copying
+    - debian/patches/CVE-2019-12450.patch: limit access to file when
+      copying in file_copy_fallback in file gio/gfile.c.
+    - CVE-2019-12450
+
+ -- Leonidas S. Barbosa <leo.barbosa@canonical.com>  Wed, 05 Jun 2019 13:47:02 -0300
+
 glib2.0 (2.56.4-0ubuntu0.18.04.2) bionic; urgency=medium
 
   * Backport upstream patches to fix GVariant alignment tests
diff -Nru glib2.0-2.56.4/debian/patches/CVE-2019-12450.patch glib2.0-2.56.4/debian/patches/CVE-2019-12450.patch
--- glib2.0-2.56.4/debian/patches/CVE-2019-12450.patch	1970-01-01 00:00:00.000000000 +0000
+++ glib2.0-2.56.4/debian/patches/CVE-2019-12450.patch	2019-06-05 16:46:56.000000000 +0000
@@ -0,0 +1,50 @@
+From d8f8f4d637ce43f8699ba94c9b7648beda0ca174 Mon Sep 17 00:00:00 2001
+From: Ondrej Holy <oholy@redhat.com>
+Date: Thu, 23 May 2019 10:41:53 +0200
+Subject: [PATCH] gfile: Limit access to files when copying
+
+file_copy_fallback creates new files with default permissions and
+set the correct permissions after the operation is finished. This
+might cause that the files can be accessible by more users during
+the operation than expected. Use G_FILE_CREATE_PRIVATE for the new
+files to limit access to those files.
+---
+ gio/gfile.c | 11 ++++++-----
+ 1 file changed, 6 insertions(+), 5 deletions(-)
+
+Index: glib2.0-2.56.4/gio/gfile.c
+===================================================================
+--- glib2.0-2.56.4.orig/gio/gfile.c
++++ glib2.0-2.56.4/gio/gfile.c
+@@ -3279,12 +3279,12 @@ file_copy_fallback (GFile
+         out = (GOutputStream*)_g_local_file_output_stream_replace (_g_local_file_get_filename (G_LOCAL_FILE (destination)),
+                                                                    FALSE, NULL,
+                                                                    flags & G_FILE_COPY_BACKUP,
+-                                                                   G_FILE_CREATE_REPLACE_DESTINATION,
+-                                                                   info,
++                                                                   G_FILE_CREATE_REPLACE_DESTINATION |
++                                                                   G_FILE_CREATE_PRIVATE, info,
+                                                                    cancellable, error);
+       else
+         out = (GOutputStream*)_g_local_file_output_stream_create (_g_local_file_get_filename (G_LOCAL_FILE (destination)),
+-                                                                  FALSE, 0, info,
++                                                                  FALSE, G_FILE_CREATE_PRIVATE, info,
+                                                                   cancellable, error);
+     }
+   else if (flags & G_FILE_COPY_OVERWRITE)
+@@ -3292,12 +3292,13 @@ file_copy_fallback (GFile
+       out = (GOutputStream *)g_file_replace (destination,
+                                              NULL,
+                                              flags & G_FILE_COPY_BACKUP,
+-                                             G_FILE_CREATE_REPLACE_DESTINATION,
++                                             G_FILE_CREATE_REPLACE_DESTINATION |
++                                             G_FILE_CREATE_PRIVATE,
+                                              cancellable, error);
+     }
+   else
+     {
+-      out = (GOutputStream *)g_file_create (destination, 0, cancellable, error);
++      out = (GOutputStream *)g_file_create (destination, G_FILE_CREATE_PRIVATE, cancellable, error);
+     }
+ 
+   if (!out)
diff -Nru glib2.0-2.56.4/debian/patches/series glib2.0-2.56.4/debian/patches/series
--- glib2.0-2.56.4/debian/patches/series	2019-03-22 12:17:34.000000000 +0000
+++ glib2.0-2.56.4/debian/patches/series	2019-06-05 16:46:52.000000000 +0000
@@ -19,3 +19,4 @@
 exp_git_default_per_desktop2.patch
 exp_git_default_per_desktop3.patch
 exp_git_default_per_desktop4.patch
+CVE-2019-12450.patch