diff --git a/gnu/local.mk b/gnu/local.mk
index 181212c70b..b7c98aeef2 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1650,6 +1650,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/xf86-video-voodoo-pcitag.patch		\
   %D%/packages/patches/xfce4-panel-plugins.patch		\
   %D%/packages/patches/xfce4-settings-defaults.patch		\
+  %D%/packages/patches/xorg-server-CVE-2020-14347.patch		\
   %D%/packages/patches/xplanet-1.3.1-cxx11-eof.patch		\
   %D%/packages/patches/xplanet-1.3.1-libdisplay_DisplayOutput.cpp.patch	\
   %D%/packages/patches/xplanet-1.3.1-libimage_gif.c.patch	\
diff --git a/gnu/packages/patches/xorg-server-CVE-2020-14347.patch b/gnu/packages/patches/xorg-server-CVE-2020-14347.patch
new file mode 100644
index 0000000000..c54b93d764
--- /dev/null
+++ b/gnu/packages/patches/xorg-server-CVE-2020-14347.patch
@@ -0,0 +1,33 @@
+From aac28e162e5108510065ad4c323affd6deffd816 Mon Sep 17 00:00:00 2001
+From: Matthieu Herrb <matthieu@herrb.eu>
+Date: Sat, 25 Jul 2020 19:33:23 +0200
+Subject: [PATCH] fix for ZDI-11426
+
+Avoid leaking un-initalized memory to clients by zeroing the
+whole pixmap on initial allocation.
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
+
+Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
+Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
+---
+ dix/pixmap.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/dix/pixmap.c b/dix/pixmap.c
+index 1186d7dbb..5a0146bbb 100644
+--- a/dix/pixmap.c
++++ b/dix/pixmap.c
+@@ -116,7 +116,7 @@ AllocatePixmap(ScreenPtr pScreen, int pixDataSize)
+     if (pScreen->totalPixmapSize > ((size_t) - 1) - pixDataSize)
+         return NullPixmap;
+ 
+-    pPixmap = malloc(pScreen->totalPixmapSize + pixDataSize);
++    pPixmap = calloc(1, pScreen->totalPixmapSize + pixDataSize);
+     if (!pPixmap)
+         return NullPixmap;
+ 
+-- 
+2.27.0
+
diff --git a/gnu/packages/xorg.scm b/gnu/packages/xorg.scm
index b58a5521ca..560e6b6a1c 100644
--- a/gnu/packages/xorg.scm
+++ b/gnu/packages/xorg.scm
@@ -5327,6 +5327,7 @@ over Xlib, including:
   (package
     (name "xorg-server")
     (version "1.20.8")
+    (replacement xorg-server/fixed)
     (source
       (origin
         (method url-fetch)
@@ -5450,6 +5451,16 @@ communicates with the user via graphical controls such as buttons and
 draggable titlebars and borders.")
     (license license:x11)))
 
+(define xorg-server/fixed  ; Fixes CVE-2020-14347
+  (package
+    (inherit xorg-server)
+    (source
+     (origin
+       (inherit (package-source xorg-server))
+       (patches
+        (append (origin-patches (package-source xorg-server))
+                (search-patches "xorg-server-CVE-2020-14347.patch")))))))
+
 ;; This package is intended to be used when building GTK+.
 ;; Note: It's currently marked as "hidden" to avoid having two non-eq?
 ;; packages with the same name and version.
@@ -5468,8 +5479,7 @@ draggable titlebars and borders.")
                  "18bfl04ihw1jr3h0fs522nnxxq5ixjay77y9dcymnkzk23q8cndx")))))))
 
 (define-public xorg-server-xwayland
-  (package
-    (inherit xorg-server)
+  (package/inherit xorg-server
     (name "xorg-server-xwayland")
     (inputs
      `(("wayland" ,wayland)