CVE-2026-41249: CoreShop Vulnerable to Remote Code Execution (RCE) via Insecure `pull_request_target` Configuration

Synopsis

This is a remote code execution vulnerability in CoreShop, a Pimcore-based eCommerce framework, affecting versions 5.0.1 through 5.1.0-beta.1. The flaw exists in a GitHub Actions workflow file that uses the `pull_request_target` trigger while checking out and executing untrusted code from an external pull request's branch. Any unauthenticated external attacker can submit a crafted pull request to execute arbitrary commands on the GitHub Actions runner, a class of attack commonly called a 'Pwn Request'. No fix version has been published as of the CVE record date; HarborGuard tracks this advisory and will surface a patched-image rebuild the moment an upstream fix is available.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker submits a pull request to the public repository over the network, triggering the vulnerable workflow without any need for prior access to the target infrastructure.

• AuthenticationNot required

  No account credentials or elevated privileges are required; any unauthenticated external user with the ability to open a pull request can trigger the exploit.

• Victim interactionNot required

  No human victim needs to click a link or take any action; the GitHub Actions workflow fires automatically on pull request submission.

• Attack complexityDetail

  Exploit reliability is high and condition-free; the attacker only needs to craft a malicious pull request branch, with no race conditions or special environmental factors required.

Blast Radius

• The attacker executes arbitrary commands on the GitHub Actions runner, giving full control over the CI build environment for the duration of the job.
• Secrets and tokens available to the runner, including repository GITHUB_TOKEN values, deployment keys, and any injected CI secrets, are exposed and can be exfiltrated.
• The attacker can read the full contents of the repository, including private branches, configuration files, and any embedded credentials checked into source.
• Supply-chain tampering is possible: the attacker can alter build artifacts, inject malicious code into packages, or push changes if the runner token carries write permissions.