In Wireshark 2.4.0 to 2.4.1 and 2.2.0 to 2.2.9, the BT ATT dissector could crash. This was addressed in epan/dissectors/packet-btatt.c by considering a case where not all of the BTATT packets have the same encapsulation level.
https://www.wireshark.org/security/wnpa-sec-2017-42.html
https://code.wireshark.org/review/23470