X.org libXtst before 1.2.3 allows remote X servers to cause a denial of service (infinite loop) via a reply in the (1) XRecordStartOfData, (2) XRecordEndOfData, or (3) XRecordClientDied category without a client sequence and with attached data. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-7952
