diff -Nru bind9-libs-9.11.16+dfsg/debian/changelog bind9-libs-9.11.16+dfsg/debian/changelog
--- bind9-libs-9.11.16+dfsg/debian/changelog	2020-02-21 17:47:46.000000000 -0300
+++ bind9-libs-9.11.16+dfsg/debian/changelog	2020-08-11 15:43:31.000000000 -0400
@@ -1,3 +1,11 @@
+bind9-libs (1:9.11.16+dfsg-3~ubuntu1) focal; urgency=medium
+
+   * debian/patches/fix-1872118.patch: Check if pending_send
+    if set before calling dispatch_send to avoid assertion.
+    Fixes LP: #1872118.
+
+ -- Jorge Niedbalski <jorge.niedbalski@canonical.com>  Tue, 11 Aug 2020 15:43:31 -0400
+
 bind9-libs (1:9.11.16+dfsg-3~build1) focal; urgency=medium
 
   * Rebuild for Ubuntu NEW
diff -Nru bind9-libs-9.11.16+dfsg/debian/patches/0011-fix-1872117.patch bind9-libs-9.11.16+dfsg/debian/patches/0011-fix-1872117.patch
--- bind9-libs-9.11.16+dfsg/debian/patches/0011-fix-1872117.patch	1969-12-31 21:00:00.000000000 -0300
+++ bind9-libs-9.11.16+dfsg/debian/patches/0011-fix-1872117.patch	2020-08-11 15:42:26.000000000 -0400
@@ -0,0 +1,22 @@
+Description: Check if sock->pending_send is set
+before calling dispatch_send(). This would prevent
+the assertion failure in cases where a socket is not dead (closed)
+and its still pending to send data and the process_fd
+event gets triggered due a wakeup.
+
+Author: Jorge Niedbalski <jorge.niedbalski@canonical.com>
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/1872118
+Forwarded: no
+Last-Update: 2020-08-03
+
+--- bind9-libs-9.11.16+dfsg.orig/lib/isc/unix/socket.c
++++ bind9-libs-9.11.16+dfsg/lib/isc/unix/socket.c
+@@ -4050,7 +4050,7 @@ check_write:
+ 		if (!SOCK_DEAD(sock)) {
+ 			if (sock->connecting)
+ 				dispatch_connect(sock);
+-			else
++			else if (!sock->pending_send)
+ 				dispatch_send(sock);
+ 		}
+ 		unwatch_write = true;
diff -Nru bind9-libs-9.11.16+dfsg/debian/patches/series bind9-libs-9.11.16+dfsg/debian/patches/series
--- bind9-libs-9.11.16+dfsg/debian/patches/series	2020-02-20 16:21:56.000000000 -0300
+++ bind9-libs-9.11.16+dfsg/debian/patches/series	2020-08-11 15:42:43.000000000 -0400
@@ -7,3 +7,4 @@
 0008-skip-rtld-deepbind-for-dyndb.diff
 0009-Use-absolute-srcdir-path-to-protoc-c-invocation.patch
 0010-python-fix-for-dist-packages.patch
+0011-fix-1872117.patch