X.Org Server (aka xserver and xorg-server) 1.15.0 through 1.16.x before 1.16.3 allows remote authenticated users to cause a denial of service (out-of-bounds read or write) or possibly execute arbitrary code via a crafted length or index value to the (1) sprocdri3queryversion, (2) sprocdri3open, (3) sprocdri3pixmapfrombuffer, (4) sprocdri3bufferfrompixmap, (5) sprocdri3fencefromfd, (6) sprocdri3fdfromfence, (7) procpresentquerycapabilities, (8) sprocpresentqueryversion, (9) sprocpresentpixmap, (10) sprocpresentnotifymsc, (11) sprocpresentselectinput, or (12) sprocpresentquerycapabilities function in the (a) DRI3 or (b) Present extension.