Epic Games Unreal Engine 226f through 436 allows remote attackers to cause a denial of service (CPU consumption or crash) and possibly execute arbitrary code via (1) a packet with a negative size value, which is treated as a large positive number during memory allocation, or (2) a negative size value in a package file.

Unreal Tournament 2003 (ut2003) clients and servers allow remote attackers to cause a denial of service via malformed messages containing a small number of characters to UDP ports 7778 or 10777.