The msn_slp_process_msg function in libpurple/protocols/msn/slpcall.c in the MSN protocol plugin in libpurple 2.6.0 and 2.6.1, as used in Pidgin before 2.6.2, allows remote attackers to cause a denial of service (application crash) via a handwritten (aka Ink) message, related to an uninitialized variable and the incorrect "UTF16-LE" charset name.

The OSCAR protocol implementation in Pidgin before 2.5.8 misinterprets the ICQWebMessage message type as the ICQSMS message type, which allows remote attackers to cause a denial of service (application crash) via a crafted ICQ web message that triggers allocation of a large amount of memory.