OpenRefine is a free, open source tool for working with messy data. The load-language command expects a `lang` parameter from which it constructs the path of the localization file to load, of the form `translations-$LANG.json`. But when doing so in versions prior to 3.8.3, it does not check that the resulting path is in the expected directory, which means that this command could be exploited to read other JSON files on the file system. Version 3.8.3 addresses this issue.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.