It was found that when receiving a response from the server protocol data is not validated sufficiently. Upstream patch: https://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=8c29f1607a31dac0911e45a0dd3d74173822b3c9 External References: https://lists.x.org/archives/xorg-announce/2016-October/002720.html CVE assignment: http://seclists.org/oss-sec/2016/q4/17
Created libX11 tracking bugs for this issue: Affects: fedora-all [bug 1381863]