OpenRefine is a free, open source tool for data processing. A carefully crafted malicious OpenRefine project tar file can be used to trigger arbitrary code execution in the context of the OpenRefine process if a user can be convinced to import it. The vulnerability exists in all versions of OpenRefine up to and including 3.7.3. Users should update to OpenRefine 3.7.4 as soon as possible. Users unable to upgrade should only import OpenRefine projects from trusted sources.