There is a HIGH severity vulnerability affecting the CPython "zipfile" module.
When iterating over names of entries in a zip archive (for example, methods of "zipfile.ZipFile" like "namelist()", "iterdir()", "extractall()", etc) the process can be put into an infinite loop with a maliciously crafted zip archive. This defect applies when reading only metadata or extracting the contents of the zip archive. Programs that are not handling user-controlled zip archives are not affected.