Index: /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibVideo.cpp
===================================================================
--- /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibVideo.cpp	(revision 55901)
+++ /trunk/src/VBox/Additions/common/VBoxGuestLib/VBoxGuestR3LibVideo.cpp	(revision 55902)
@@ -486,5 +486,5 @@
     {
         char c1, c2;
-        cMatches = sscanf(szModeParms, "%ux%ux%u%c%ux%u,%u%c", &cx, &cy, &cBits,
+        cMatches = sscanf(szModeParms, "%5ux%5ux%2u%c%5ux%5u,%1u%c", &cx, &cy, &cBits,
                           &c1, &x, &y, &fEnabled, &c2);
         if ((cMatches == 7 && c1 == ',') || cMatches == 3)