Firejail does not properly clean environment variables, which allows local users to gain privileges.

Firejail uses 0777 permissions when mounting (1) /dev, (2) /dev/shm, (3) /var/tmp, or (4) /var/lock, which allows local users to gain privileges.

Firejail does not restrict access to --tmpfs, which allows local users to gain privileges, as demonstrated by mounting over /etc.

Firejail before 0.9.44.4, when running a bandwidth command, allows local users to gain root privileges via the --shell argument.

Firejail before 0.9.44.4, when running on a Linux kernel before 4.8, allows context-dependent attackers to bypass a seccomp-based sandbox protection mechanism via the --allow-debuggers argument.

Firejail before 0.9.44.6 and 0.9.38.x LTS before 0.9.38.10 LTS does not comprehensively address dotfile cases during its attempt to prevent accessing user files with an euid of zero, which allows local users to conduct sandbox-escape attacks via vectors involving a symlink and the --private option. NOTE: this vulnerability exists because of an incomplete fix for CVE-2017-5180.

Firejail before 0.9.44.4 and 0.9.38.x LTS before 0.9.38.8 LTS does not consider the .Xauthority case during its attempt to prevent accessing user files with an euid of zero, which allows local users to conduct sandbox-escape attacks via vectors involving a symlink and the --private option.

Firejail 0.9.38.4 allows local users to execute arbitrary commands outside of the sandbox via a crafted TIOCSTI ioctl call.