Memory leak in Cisco IOS 12.4, 15.0, and 15.1, Cisco IOS XE 2.5.x through 3.2.x, and Cisco Unified Communications Manager (CUCM) 6.x and 7.x before 7.1(5b)su4, 8.x before 8.5(1)su2, and 8.6 before 8.6(1) allows remote attackers to cause a denial of service (memory consumption and device reload or process failure) via a malformed SIP message, aka Bug IDs CSCtl86047 and CSCto88686.