c-ares is a C library for asynchronous DNS requests. `ares__read_line()` is used to parse local configuration files such as `/etc/resolv.conf`, `/etc/nsswitch.conf`, the `HOSTALIASES` file, and if using a c-ares version prior to 1.27.0, the `/etc/hosts` file. If any of these configuration files has an embedded `NULL` character as the first character in a new line, it can lead to attempting to read memory prior to the start of the given buffer which may result in a crash. This issue is fixed in c-ares 1.27.0. No known workarounds exist.
https://github.com/c-ares/c-ares/security/advisories/GHSA-mg26-v6qh-x48q
https://github.com/c-ares/c-ares/commit/a804c04ddc8245fc8adf0e92368709639125e183