IceWeasel-75.0-1.parabola2 brings an important update to the default configuration. We are relaxing the WebRTC privacy settings to allow Jitsi to function, bringing fully free video conferencing to parabola GNU/Linux-libre. The flip side of this change is that under certain circumstances this may be exploited in a way that the browser may leak local addresses in VPN connections. The browser extension 'uBlock Origin' provides a setting to prevent this from happening, and we are investigating ways to harden IceWeasel against such attacks.
In the meantime, to retain the old behaviour, set 'media.peerconnection.enabled' to 'false' in about:config.