Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. Prior to version 0.9-rc4, any unprivileged local user can crash avahi-daemon by sending a single D-Bus method call with conflicting publish flags. This issue has been patched in version 0.9-rc4.
https://github.com/avahi/avahi/security/advisories/GHSA-w65r-6gxh-vhvc
https://github.com/avahi/avahi/pull/891
https://github.com/avahi/avahi/commit/625ca0fac19229f6dfa3a6c6b698ae657187e50c