Contiki-NG is an open-source, cross-platform operating system for internet of things devices. In versions prior to 4.5, buffer overflow can be triggered by an input packet when using either of Contiki-NG's two RPL implementations in source-routing mode. The problem has been patched in Contiki-NG 4.5. Users can apply the patch for this vulnerability out-of-band as a workaround.