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	2020-08-12 07:43:31.000000000 +1200
+++ bind9-libs-9.11.16+dfsg/debian/changelog	2023-01-16 10:02:00.000000000 +1300
@@ -1,3 +1,16 @@
+bind9-libs (1:9.11.16+dfsg-3~ubuntu1.1) focal; urgency=medium
+
+  * debian/rules: Ensure --disable-threads is set to prevent
+    isc-dhcp running as multithreaded. Fixes a thread
+    concurrency race condition in isc-dhcp that closes the read
+    socket, which prevents DHCPOFFERS from ever being received.
+  * debian/libirs161.symbols: Update symbols.
+  * debian/libisc1105.symbols: Update symbols. Multithread
+    symbols have been REMOVED.
+    (LP: #1926139)
+
+ -- Matthew Ruffell <matthew.ruffell@canonical.com>  Mon, 16 Jan 2023 10:02:00 +1300
+
 bind9-libs (1:9.11.16+dfsg-3~ubuntu1) focal; urgency=medium
 
    * debian/patches/fix-1872118.patch: Check if pending_send
diff -Nru bind9-libs-9.11.16+dfsg/debian/libirs161.symbols bind9-libs-9.11.16+dfsg/debian/libirs161.symbols
--- bind9-libs-9.11.16+dfsg/debian/libirs161.symbols	2020-02-21 08:21:56.000000000 +1300
+++ bind9-libs-9.11.16+dfsg/debian/libirs161.symbols	2023-01-16 10:02:00.000000000 +1300
@@ -17,6 +17,7 @@
  irs_dnsconf_destroy@Base 1:9.10.6+dfsg
  irs_dnsconf_gettrustedkeys@Base 1:9.10.6+dfsg
  irs_dnsconf_load@Base 1:9.10.6+dfsg
+ irs_g_context@Base 1:9.11.16+dfsg-3~ubuntu1.1
  irs_libage@Base 1:9.10.6+dfsg
  irs_libinterface@Base 1:9.10.6+dfsg
  irs_librevision@Base 1:9.10.6+dfsg
diff -Nru bind9-libs-9.11.16+dfsg/debian/libisc1105.symbols bind9-libs-9.11.16+dfsg/debian/libisc1105.symbols
--- bind9-libs-9.11.16+dfsg/debian/libisc1105.symbols	2020-02-21 08:21:56.000000000 +1300
+++ bind9-libs-9.11.16+dfsg/debian/libisc1105.symbols	2023-01-16 10:02:00.000000000 +1300
@@ -86,7 +86,8 @@
  isc__mempool_setfreemax@Base 1:9.11.3+dfsg
  isc__mempool_setmaxalloc@Base 1:9.11.3+dfsg
  isc__mempool_setname@Base 1:9.11.3+dfsg
- isc__mutex_init@Base 1:9.11.3+dfsg
+ isc__nothread_signal_hack@Base 1:9.11.16+dfsg-3~ubuntu1.1
+ isc__nothread_wait_hack@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc__socket_accept@Base 1:9.11.3+dfsg
  isc__socket_attach@Base 1:9.11.3+dfsg
  isc__socket_bind@Base 1:9.11.3+dfsg
@@ -126,8 +127,10 @@
  isc__socketmgr_create2@Base 1:9.11.3+dfsg
  isc__socketmgr_create@Base 1:9.11.3+dfsg
  isc__socketmgr_destroy@Base 1:9.11.3+dfsg
+ isc__socketmgr_dispatch@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc__socketmgr_maxudp@Base 1:9.11.3+dfsg
  isc__socketmgr_setreserved@Base 1:9.11.3+dfsg
+ isc__socketmgr_waitevents@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc__strerror@Base 1:9.11.3+dfsg
  isc__task_attach@Base 1:9.11.3+dfsg
  isc__task_beginexclusive@Base 1:9.11.3+dfsg
@@ -153,9 +156,9 @@
  isc__task_unsendrange@Base 1:9.11.3+dfsg
  isc__taskmgr_create@Base 1:9.11.3+dfsg
  isc__taskmgr_destroy@Base 1:9.11.3+dfsg
+ isc__taskmgr_dispatch@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc__taskmgr_mode@Base 1:9.11.3+dfsg
- isc__taskmgr_pause@Base 1:9.11.3+dfsg
- isc__taskmgr_resume@Base 1:9.11.3+dfsg
+ isc__taskmgr_ready@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc__taskmgr_setmode@Base 1:9.11.3+dfsg
  isc__timer_attach@Base 1:9.11.3+dfsg
  isc__timer_create@Base 1:9.11.3+dfsg
@@ -165,6 +168,8 @@
  isc__timer_touch@Base 1:9.11.3+dfsg
  isc__timermgr_create@Base 1:9.11.3+dfsg
  isc__timermgr_destroy@Base 1:9.11.3+dfsg
+ isc__timermgr_dispatch@Base 1:9.11.16+dfsg-3~ubuntu1.1
+ isc__timermgr_nextevent@Base 1:9.11.16+dfsg-3~ubuntu1.1
  isc_aes128_crypt@Base 1:9.11.3+dfsg
  isc_aes192_crypt@Base 1:9.11.3+dfsg
  isc_aes256_crypt@Base 1:9.11.3+dfsg
@@ -236,7 +241,6 @@
  isc_commandline_progname@Base 1:9.11.3+dfsg
  isc_commandline_reset@Base 1:9.11.3+dfsg
  isc_commandline_strtoargv@Base 1:9.11.3+dfsg
- isc_condition_waituntil@Base 1:9.11.3+dfsg
  isc_counter_attach@Base 1:9.11.3+dfsg
  isc_counter_create@Base 1:9.11.3+dfsg
  isc_counter_detach@Base 1:9.11.3+dfsg
@@ -805,10 +809,8 @@
  isc_taskpool_gettask@Base 1:9.11.3+dfsg
  isc_taskpool_setprivilege@Base 1:9.11.3+dfsg
  isc_taskpool_size@Base 1:9.11.3+dfsg
- isc_thread_create@Base 1:9.11.3+dfsg
  isc_thread_setconcurrency@Base 1:9.11.3+dfsg
  isc_thread_setname@Base 1:9.11.3+dfsg
- isc_thread_yield@Base 1:9.11.3+dfsg
  isc_time_add@Base 1:9.11.3+dfsg
  isc_time_compare@Base 1:9.11.3+dfsg
  isc_time_epoch@Base 1:9.11.3+dfsg
diff -Nru bind9-libs-9.11.16+dfsg/debian/rules bind9-libs-9.11.16+dfsg/debian/rules
--- bind9-libs-9.11.16+dfsg/debian/rules	2020-02-21 08:21:56.000000000 +1300
+++ bind9-libs-9.11.16+dfsg/debian/rules	2023-01-16 10:01:48.000000000 +1300
@@ -47,7 +47,6 @@
 	--enable-rrl \
 	--enable-shared \
 	--enable-static \
-	--enable-threads \
 	--localstatedir=/ \
 	--sysconfdir=/etc/bind \
 	--with-atf=no \