diff --git a/tftp-off-by-one.patch b/tftp-off-by-one.patch
new file mode 100644
index 0000000..98b0874
--- /dev/null
+++ b/tftp-off-by-one.patch
@@ -0,0 +1,44 @@
+Resolves: #1485943
+
+--- a/tftpd/tftpd.c       2017-08-28 09:12:11.681299000 +0200
++++ b/tftpd/tftpd.c       2017-08-28 13:30:03.109312000 +0200
+@@ -1388,24 +1388,25 @@
+             return strlen(p);
+ 
+     case 'x':
+-        if (output) {
+-            if (from.sa.sa_family == AF_INET) {
++        if (from.sa.sa_family == AF_INET) {
++            if (output) {
+                 sprintf(output, "%08lX",
+                     (unsigned long)ntohl(from.si.sin_addr.s_addr));
+-                l = 8;
++            }
++            l = 8;
+ #ifdef HAVE_IPV6
+-            } else {
+-                unsigned char *c = (unsigned char *)SOCKADDR_P(&from);
+-                p = tb;
+-                for (l = 0; l < 16; l++) {
+-                    sprintf(p, "%02X", *c);
+-                    c++;
+-                    p += 2;
+-                }
++        } else {
++            unsigned char *c = (unsigned char *)SOCKADDR_P(&from);
++            p = tb;
++            for (l = 0; l < 16; l++) {
++                sprintf(p, "%02X", *c);
++                c++;
++                p += 2;
++            }
++            if (output)
+                 strcpy(output, tb);
+-                l = strlen(tb);
++            l = strlen(tb);
+ #endif
+-            }
+         }
+         return l;
+ 
+
diff --git a/tftp.spec b/tftp.spec
index c126931..6ec19ab 100644
--- a/tftp.spec
+++ b/tftp.spec
@@ -22,6 +22,7 @@ Patch8: tftp-hpa-5.2-pktinfo.patch
 Patch9: tftp-doc.patch
 Patch10: tftp-enhanced-logging.patch
 Patch11: tftp-hpa-5.2-gcc10.patch
+Patch12: tftp-off-by-one.patch
 
 BuildRequires: make
 BuildRequires:  gcc
@@ -61,6 +62,7 @@ systemd socket activation, and is disabled by default.
 %patch9 -p1 -b .doc
 %patch10 -p1 -b .logging
 %patch11 -p1 -b .gcc10
+%patch12 -p1 -b .off-by-one
 
 %build
 autoreconf
@@ -105,6 +107,8 @@ install -p -m 644 %SOURCE2 ${RPM_BUILD_ROOT}%{_unitdir}
 %changelog
 * Tue Mar 29 2022 Dominik Mierzejewski <dominik@greysector.net> - 5.2-33
 - fix the --mapfile/--map-file discrepancy in the manual page (Lukáš Zaoral)
+- fix off-by-one reads and writes when filename remapping with macro \x is used
+  (Lukáš Zaoral)
 
 * Wed Jan 27 2021 Fedora Release Engineering <releng@fedoraproject.org> - 5.2-32
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild