Mandriva Linux Security Advisory 2013-260 - Multiple vulnerabilities have been discovered and corrected in x11-server. The updated packages have been patched to correct these issues.
50969d2a09bdf2e48ce14b12843f678f7e90396dd3d3c735132e96cfb2be5013
Ubuntu Security Notice 939-1 - L. Minier discovered that xvfb-run did not correctly keep the X.org session cookie private. A local attacker could gain access to any local sessions started by xvfb-run. Ubuntu 9.10 was not affected. It was discovered that the X.org server did not correctly handle certain calculations. A remote attacker could exploit this to crash the X.org session or possibly run arbitrary code with root privileges.
466665fb9452b0aa9be41ad90905f0c837e714353885c083397f02f9e27b496f