See https://nlnetlabs.nl/pipermail/unbound-users/2019-November/011897.html
This release is a fix for vulnerability CVE-2019-18934, that can cause
shell execution in ipsecmod.Bug Fixes:
- Fix for the reported vulnerability.
The CVE number for this vulnerability is CVE-2019-18934
== Summary
Recent versions of Unbound contain a vulnerability that can cause shell
code execution after receiving a specially crafted answer. This issue
can only be triggered if unbound was compiled with--enable-ipsecmod
support, and ipsecmod is enabled and used in the configuration.== Affected products
Unbound 1.6.4 up to and including 1.9.4.