In the git-tag-annotation-action (open source GitHub Action) before version 1.0.1, an attacker can execute arbitrary (*) shell commands if they can control the value of [the tag
input] or manage to alter the value of [the GITHUB_REF
environment variable]. The problem has been patched in version 1.0.1. If you don't use the tag
input you are most likely safe. The GITHUB_REF
environment variable is protected by the GitHub Actions environment so attacks from there should be impossible. If you must use the tag
input and cannot upgrade to > 1.0.0
make sure that the value is not controlled by another Action.