diff --git a/0001-security-Document-assignment-of-CVE-2021-20286.patch b/0001-security-Document-assignment-of-CVE-2021-20286.patch
new file mode 100644
index 0000000..ca96878
--- /dev/null
+++ b/0001-security-Document-assignment-of-CVE-2021-20286.patch
@@ -0,0 +1,39 @@
+From 40308a005eaa6b2e8f98da8952d0c0cacc51efde Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Fri, 12 Mar 2021 17:00:58 -0600
+Subject: [PATCH] security: Document assignment of CVE-2021-20286
+
+Now that we finally have a CVE number, it's time to document
+the problem (it's low severity, but still a denial of service).
+
+Fixes: fb4440de9cc7 (opt_go: Tolerate unplanned server death)
+---
+ docs/libnbd-security.pod | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/docs/libnbd-security.pod b/docs/libnbd-security.pod
+index 876ef2f..3c994de 100644
+--- a/docs/libnbd-security.pod
++++ b/docs/libnbd-security.pod
+@@ -22,6 +22,12 @@ L<https://www.redhat.com/archives/libguestfs/2019-September/msg00128.html>
+ See the full announcement here:
+ L<https://www.redhat.com/archives/libguestfs/2019-October/msg00060.html>
+ 
++=head2 CVE-2021-20286
++denial of service when using L<nbd_set_opt_mode(3)>
++
++See the full announcement here:
++L<https://listman.redhat.com/archives/libguestfs/2021-March/msg00092.html>
++
+ =head1 SEE ALSO
+ 
+ L<libnbd(3)>.
+@@ -34,4 +40,4 @@ Richard W.M. Jones
+ 
+ =head1 COPYRIGHT
+ 
+-Copyright (C) 2019 Red Hat Inc.
++Copyright (C) 2019-2021 Red Hat Inc.
+-- 
+2.29.0.rc2
+
diff --git a/libnbd.spec b/libnbd.spec
index 901cb5f..a4131cb 100644
--- a/libnbd.spec
+++ b/libnbd.spec
@@ -9,7 +9,7 @@
 
 Name:           libnbd
 Version:        1.7.3
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        NBD client library in userspace
 
 License:        LGPLv2+
@@ -35,6 +35,9 @@ Patch0005:      0005-copy-file-ops.c-Fix-page-eviction-when-len-page_size.patch
 # Upstream patch to fix nbdkit test suite.
 Patch0006:      0006-info-Let-exit-status-reflect-any-failures-during-NBD.patch
 
+# Upstream patch that documents CVE-2021-20286 (already fixed in 1.7.3).
+Patch0007:      0001-security-Document-assignment-of-CVE-2021-20286.patch
+
 %if 0%{patches_touch_autotools}
 BuildRequires: autoconf, automake, libtool
 %endif
@@ -311,6 +314,9 @@ make %{?_smp_mflags} check || {
 
 
 %changelog
+* Mon Mar 15 2021 Richard W.M. Jones <rjones@redhat.com> - 1.7.3-3
+- Update documentation for CVE-2021-20286.
+
 * Thu Mar  4 2021 Richard W.M. Jones <rjones@redhat.com> - 1.7.3-2
 - Add fix for nbdkit test suite.