diff --git a/SOURCES/unbound-1.7.3-auth-callback.patch b/SOURCES/unbound-1.7.3-auth-callback.patch
new file mode 100644
index 0000000..57a8922
--- /dev/null
+++ b/SOURCES/unbound-1.7.3-auth-callback.patch
@@ -0,0 +1,65 @@
+--- a/services/authzone.c	2018-06-14 09:09:01.000000000 +0200
++++ b/services/authzone.c	2020-04-16 18:55:50.806693241 +0200
+@@ -5139,7 +5139,7 @@
+ 	log_assert(xfr->task_transfer);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_transfer->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return; /* stop on quit */
+ 	}
+@@ -5558,7 +5558,7 @@
+ 	log_assert(xfr->task_transfer);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_transfer->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return 0; /* stop on quit */
+ 	}
+@@ -5619,7 +5619,7 @@
+ 	log_assert(xfr->task_transfer);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_transfer->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return 0; /* stop on quit */
+ 	}
+@@ -5798,7 +5798,7 @@
+ 	log_assert(xfr->task_probe);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_probe->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return; /* stop on quit */
+ 	}
+@@ -5829,7 +5829,7 @@
+ 	log_assert(xfr->task_probe);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_probe->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return 0; /* stop on quit */
+ 	}
+@@ -6030,7 +6030,7 @@
+ 	log_assert(xfr->task_probe);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_probe->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return; /* stop on quit */
+ 	}
+@@ -6089,7 +6089,7 @@
+ 	log_assert(xfr->task_nextprobe);
+ 	lock_basic_lock(&xfr->lock);
+ 	env = xfr->task_nextprobe->env;
+-	if(env->outnet->want_to_quit) {
++	if(!env || env->outnet->want_to_quit) {
+ 		lock_basic_unlock(&xfr->lock);
+ 		return; /* stop on quit */
+ 	}
diff --git a/SPECS/unbound.spec b/SPECS/unbound.spec
index 351185a..c151044 100644
--- a/SPECS/unbound.spec
+++ b/SPECS/unbound.spec
@@ -34,7 +34,7 @@
 Summary: Validating, recursive, and caching DNS(SEC) resolver
 Name: unbound
 Version: 1.7.3
-Release: 10%{?extra_version:.%{extra_version}}%{?dist}
+Release: 11%{?extra_version:.%{extra_version}}%{?dist}
 License: BSD
 Url: https://www.unbound.net/
 Source: https://www.unbound.net/downloads/%{name}-%{version}%{?extra_version}.tar.gz
@@ -61,6 +61,7 @@ Patch4: unbound-1.7.3-anchor-fallback.patch
 Patch5: unbound-1.7.3-host-any.patch
 Patch6: unbound-1.7.3-use-basic-lock.patch
 Patch7: unbound-1.7.3-ipsec-hook.patch
+Patch8: unbound-1.7.3-auth-callback.patch
 
 BuildRequires: gcc, make
 BuildRequires: flex, openssl-devel
@@ -162,6 +163,7 @@ pushd %{pkgname}
 %patch5 -p1 -b .host-any
 %patch6 -p1 -b .use-basic-lock
 %patch7 -p1 -b .ipsec-hook
+%patch8 -p1 -b .auth-callback
 
 # only for snapshots
 # autoreconf -iv
@@ -433,6 +435,9 @@ popd
 %attr(0644,root,root) %config %{_sysconfdir}/%{name}/root.key
 
 %changelog
+* Thu Apr 16 2020 Artem Egorenkov <aegorenk@redhat.com> - 1.7.3-11
+- Resolves bz1818761. unbound crash fixed.
+
 * Tue Dec 10 2019 Tomas Korbar <tkorbar@redhat.com> - 1.7.3-10
 - Secure ipsec mode (#1772061)
 - CVE-2019-18934