Heap-based buffer overflow in Xchat-WDK before 1499-4 (2012-01-18) xchat 2.8.6 on Maemo architecture could allow remote attackers to cause a denial of service (xchat client crash) or execute arbitrary code via a UTF-8 line from server containing characters outside of the Basic Multilingual Plane (BMP).

Heap-based buffer overflow in XChat 2.8.9 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long response string.

Untrusted search path vulnerability in the Python module in xchat allows local users to execute arbitrary code via a Trojan horse Python file in the current working directory, related to a vulnerability in the PySys_SetArgv function (CVE-2008-5983).

Argument injection vulnerability in XChat 2.8.7b and earlier on Windows, when Internet Explorer is used, allows remote attackers to execute arbitrary commands via the --command parameter in an ircs:// URI.

Unspecified vulnerability in Xchat 2.6.7 and earlier allows remote attackers to cause a denial of service (crash) via unspecified vectors involving the PRIVMSG command. NOTE: the vendor has disputed this vulnerability, stating that it does not affect 2.6.7 "or any recent version"

XChat IRC client allows remote attackers to execute arbitrary commands via a /dns command on a host whose DNS reverse lookup contains shell metacharacters.

IRC Xchat client versions 1.4.2 and earlier allows remote attackers to execute arbitrary commands by encoding shell metacharacters into a URL which XChat uses to launch a web browser.