gouef githubtoplanguages command injection in Discord notification workflow

Executive brief

A vulnerability in the githubtoplanguages GitHub Action allows an attacker to execute malicious commands by creating an issue with a specially crafted title. This component is used to automate Discord notifications for repository activity. An exploit could allow an attacker to steal sensitive credentials like Discord webhooks, manipulate automated messages, or gain unauthorized access to the GitHub Actions runner environment.

Technical details

The vulnerability exists in the `.github/workflows/discord-issue.yml` workflow where `github.event.issue.title` or `github.event.pull_request.title` is directly interpolated into a Bash script assignment. Because GitHub Actions expressions are expanded before the shell executes the script, an attacker can use command substitution syntax (e.g., $(whoami)) in an issue title to achieve arbitrary code execution on the runner. This can be used to exfiltrate secrets like the `DISCORD_WEBHOOK` or other environment variables. The issue is fixed in version 1.1.4 by passing user-controlled data through environment variables instead of direct interpolation.

Affected products

• gouef githubtoplanguages < 1.1.4

Timeline

• 2026-06-19: disclosed
• 2026-06-19: patched: Fixed in version 1.1.4
• 2026-06-19: advisory

References

• https://api.github.com/users/choseogyeong
• https://github.com/choseogyeong
• https://api.github.com/users/choseogyeong/gists%7B/gist_id%7D
• https://api.github.com/users/choseogyeong/repos
• https://avatars.githubusercontent.com/u/69794629?v=4
• https://api.github.com/users/choseogyeong/events%7B/privacy%7D