Executive brief
MaaAssistantArknights, a tool for automating tasks in the game Arknights, contained a security flaw in its automated release process on GitHub. An attacker could submit a specially crafted pull request that triggers the execution of unauthorized commands on the project's build servers. While this could allow an attacker to disrupt the development process or abuse computing resources, it does not directly expose sensitive organizational secrets or allow unauthorized changes to the main code repository.
Technical details
A command injection vulnerability exists in the `release-preparation.yml` workflow of MaaAssistantArknights due to the unsafe inlining of GitHub Actions expressions. Specifically, the `github.event.pull_request.title` is directly embedded into a bash `run` script using `${{ }}` syntax. Because this expansion occurs before the shell executes, an attacker can use shell metacharacters (e.g., backticks or command substitution) in a Pull Request title to achieve Remote Code Execution (RCE) on the `ubuntu-latest` runner. The vulnerability is reachable from fork PRs without maintainer approval, though the impact is limited to the ephemeral runner environment as the `GITHUB_TOKEN` is read-only for forks. The issue was fixed by binding the PR title to an environment variable instead of inlining it.
Affected products
- MaaAssistantArknights MaaAssistantArknights dev-v2 branch before commit cafc3946059e6337d2089d4fec8b6885ba17c332
Timeline
- 2026-06-14: advisory: GitHub Security Advisory published
- 2026-07-15: disclosed: CVE published to NVD