CVE-2026-45131: CloudPirates Open Source Helm Charts: GitHub Actions pull_request_target workflow allows secret exfiltration via fork pull requests

Synopsis

This is a CI/CD privilege-escalation vulnerability in the CloudPirates Open Source Helm Charts GitHub Actions workflow. An unauthenticated external attacker can open a fork pull request that triggers the pull-request.yaml workflow in a privileged context, where it runs attacker-controlled code with access to repository secrets. Successful exploitation gives the attacker full read access to secrets such as Docker Hub credentials and tokens, and the ability to tamper with any resource those credentials can reach. HarborGuard tracks this advisory and will make a patched-image rebuild available the moment an upstream fix version is published to a package registry.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker reaches the target over the network by submitting a fork pull request to the public GitHub repository, with no need for local or physical access.

• AuthenticationNot required

  No GitHub account privileges are required beyond the ability to open a pull request, which is available to any unauthenticated or anonymous-registered user.

• Victim interactionNot required

  The vulnerable workflow triggers automatically on pull_request_target events without any maintainer review or approval action.

• Attack complexityDetail

  Exploitation is reliable and condition-free; the attacker simply submits a fork PR and the privileged workflow executes their code unconditionally.

Blast Radius

• Reads repository secrets in their entirety, including Docker Hub credentials and access tokens scoped to the repository.
• Uses exfiltrated Docker Hub credentials to push malicious or backdoored images to the project's container registries.
• Modifies repository contents or published Helm chart artifacts by leveraging the token permissions granted to the workflow context.