In Wireshark 2.6.0, 2.4.0 to 2.4.6, and 2.2.0 to 2.2.14, the Q.931 dissector could crash. This was addressed in epan/dissectors/packet-q931.c by avoiding a use-after-free after a malformed packet prevented certain cleanup.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:H7.5/CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H