core.py in Mitogen before 0.2.8 has a typo that drops the unidirectional-routing protection mechanism in the case of a child that is initiated by another child. The Ansible extension is unaffected. NOTE: the vendor disputes this issue because it is exploitable only in conjunction with hypothetical other factors, i.e., an affected use case within a library caller, and a bug in the message receiver policy code that led to reliance on this extra protection mechanism
https://mitogen.networkgenomics.com/changelog.html#v0-2-8-2019-08-18
https://github.com/dw/mitogen/commit/5924af1566763e48c42028399ea0cd95c457b3dc