CVE-2011-5129

CVE-2011-5129 describes a heap-based buffer overflow vulnerability in XChat 2.8.9 and earlier versions. This flaw allows remote attackers to trigger a denial of service (application crash) and potentially execute arbitrary code by sending a specially crafted, long response string. The vulnerability has a CVSS score of 5.0, indicating a medium severity, with low attack complexity and no authentication required for exploitation. While not listed on the KEV catalog, a public denial-of-service exploit is available on ExploitDB, though there is no evidence of active exploitation or significant community discussion.