rxvt-unicode before 6.3, on certain platforms that use openpty and non-Unix pty devices such as Linux and most BSD platforms, does not maintain the intended permissions of tty devices, which allows local users to gain read and write access to the devices.

Cross-site scripting (XSS) vulnerability in the Unicode version of msearch (unicode-msearch) 1.51(U1)-beta1, 1.51(U1), and 1.52(U1) allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Buffer overflow in command.C for rxvt-unicode before 5.3 allows remote attackers to execute arbitrary code via a crafted file containing long escape sequences.

RXVT-Unicode 3.4 and 3.5 does not properly close file descriptors, which allows local users to access the terminals of other users and possibly gain privileges.