Junglewise Threat Intelligence

CVE-2026-47690: Meltano MeltanoHub command injection in test_dispatcher workflow

CVE-2026-47690 · Severity: high · CVSS 7.5 · Published 2026-07-21

Executive brief

MeltanoHub is the central repository for Meltano plugins. A security flaw in its automated testing workflows allowed unauthorized individuals to execute malicious commands by simply submitting a specially crafted pull request. This could have allowed an attacker to gain write access to the repository, potentially compromising the integrity of the plugin ecosystem.

Technical details

A command injection vulnerability existed in the `test_dispatcher.yml` GitHub Actions workflow of MeltanoHub. The `get_changed_files` job used the `pull_request_target` event and unsafely interpolated the `${{ steps.changed_files.outputs.all_changed_files }}` output directly into a shell command. Because `pull_request_target` runs in the context of the base repository and has access to secrets, an attacker could trigger the vulnerability by submitting a pull request containing a file with a name designed for bash command substitution (e.g., `$(command)`). This allowed for arbitrary code execution on the runner and exfiltration of the `GITHUB_TOKEN` which, due to a lack of a permissions block, defaulted to having write access. The issue was fixed by properly scoping token permissions and using environment variables instead of direct interpolation.

Affected products

  • Meltano MeltanoHub prior to commit 923820de8f64d753951fbbd54f7282a3d5f75173

Timeline

  • 2026-04-30: patched: Initial fix PR submitted
  • 2026-05-19: advisory: GitHub Security Advisory published
  • 2026-07-21: disclosed: CVE published to NVD

References