A flaw in the WPGraphQL release workflow permits the content of a pull request body to be inserted directly into a shell command. This results in OS command injection, allowing an attacker to execute arbitrary commands on the Actions runner when a pull request from develop to master is merged. The outcome is a full compromise of the Actions runner and, by extension, the potentially sensitive environment in which the workflow runs.

The vulnerability exists in the wp-graphql/wp-graphql repository before version 2.9.1. Any WordPress site using WPGraphQL that relies on the existing GitHub Actions release workflow and has not applied the 2.9.1 update is affected.

The CVSS score of 7.7 indicates high severity, yet the EPSS score is under 1% and the flaw is not listed in the CISA KEV catalog, suggesting a low to moderate exploitation probability. The likely attack vector involves an attacker submitting a crafted pull request to the develop branch that merges into master, thereby injecting malicious code into the release workflow. Once the merge occurs, the Actions runner executes the unsanitized payload, resulting in arbitrary command execution. This scenario would require the attacker to have sufficient privilege to submit pull requests. The overall risk reflects a significant potential impact balanced against a relatively low exploitation likelihood.