jupyterlab-git is a JupyterLab extension for version control using Git. On many platforms, a third party can create a Git repository under a name that includes a shell command substitution string in the syntax $(<command>). These directory names are allowed in macOS and a majority of Linux distributions. If a user starts jupyter-lab in a parent directory of this inappropriately-named Git repository, opens it, and clicks "Git > Open Git Repository in Terminal" from the menu bar, then the injected command <command> is run in the user's shell without the user's permission. This issue is occurring because when that menu entry is clicked, jupyterlab-git opens the terminal and runs cd <git-repo-path> through the shell to set the current directory. Doing so runs any command substitution strings present in the directory name, which leads to the command injection issue described here. A previous patch provided an incomplete fix. This vulnerability is fixed in 0.51.1.