The dissect_diameter_base_framed_ipv6_prefix function in epan/dissectors/packet-diameter.c in the DIAMETER dissector in Wireshark 1.12.x before 1.12.9 and 2.0.x before 2.0.1 does not validate the IPv6 prefix length, which allows remote attackers to cause a denial of service (stack-based buffer overflow and application crash) via a crafted packet.