CVE-2016-9190
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9190

Python Imaging allows context-dependent attackers to execute arbitrary code
by using the "crafted image file" approach, related to an "Insecure Sign
Extension" issue affecting the ImagingNew in Storage.c component.

Code changes based on those found upstream for Pillow at:

https://github.com/python-pillow/Pillow/pull/2146/commits/5d8a0be45aad78c5a22c8d099118ee26ef8144af
for:
  libImaging/Storage.c

--- Imaging-1.1.7/libImaging/Storage.c.orig	2016-11-21 07:38:52.301251099 +0000
+++ Imaging-1.1.7/libImaging/Storage.c	2016-11-21 07:40:39.795030452 +0000
@@ -369,6 +369,10 @@
     } else
         bytes = strlen(mode); /* close enough */
 
+    if (xsize < 0 || ysize < 0) {
+        return (Imaging) ImagingError_ValueError("bad image size");
+    }
+
     if ((long) xsize * ysize * bytes <= THRESHOLD) {
         im = ImagingNewBlock(mode, xsize, ysize);
         if (im)