Apptainer is an open source container platform. Prior to version 1.5.1, Image.AuthorizedPath applies plain string-prefix matching to the limit container paths directive in apptainer.conf, so an allowed path such as /data/safe also authorizes a sibling path such as /data/safe-but-unsafe. A local user can consequently run a container from a directory outside the administrator's intended allowlist when Apptainer operates in setuid mode. Installations that do not use setuid mode or do not configure limit container paths are not affected, and unrestricted user namespaces already allow users to run containers of their choice. This issue is fixed in version 1.5.1.