The rxvt-unicode package is vulnerable to a remote code execution, in the Perl background extension, when an attacker can control the data written to the user's terminal and certain options are set.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:HI:HA:H9.8/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HInput Validation