The gh cli is GitHub’s official command line tool. A security vulnerability has been identified in the GitHub CLI that could leak authentication tokens when cloning repositories containing git
submodules hosted outside of GitHub.com and ghe.com. This vulnerability stems from several gh
commands used to clone a repository with submodules from a non-GitHub host including gh repo clone
, gh repo fork
, and gh pr checkout
. These GitHub CLI commands invoke git with instructions to retrieve authentication tokens using the credential.helper
configuration variable for any host encountered. Prior to version 2.63.0
, hosts other than GitHub.com and ghe.com are treated as GitHub Enterprise Server hosts and have tokens sourced from the following environment variables before falling back to host-specific tokens stored within system-specific secured storage: 1. GITHUB_ENTERPRISE_TOKEN
, 2. GH_ENTERPRISE_TOKEN
and 3. GITHUB_TOKEN
when the CODESPACES
environment variable is set. The result being git
sending authentication tokens when cloning submodules. In version 2.63.0
, these GitHub CLI commands will limit the hosts for which gh
acts as a credential helper to source authentication tokens. Additionally, GITHUB_TOKEN
will only be used for GitHub.com and ghe.com. Users are advised to upgrade. Additionally users are advised to revoke authentication tokens used with the GitHub CLI and to review their personal security log and any relevant audit logs for actions associated with their account or enterprise