rbash in Bash before 4.4-beta2 did not prevent the shell user from modifying BASH_CMDS, thus allowing the user to execute any command with the permissions of the shell.
Severity
CVSS 3.1
7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-31)