This update for libX11 fixes the following security issues: - CVE-2018-14599: The function XListExtensions was vulnerable to an off-by-one error caused by malicious server responses, leading to DoS or possibly unspecified other impact - CVE-2018-14600: The function XListExtensions interpreted a variable as signed instead of unsigned, resulting in an out-of-bounds write , leading to DoS or remote code execution - CVE-2018-14598: A malicious server could have sent a reply in which the first string overflows, causing a variable to be set to NULL that will be freed later on, leading to DoS