According to Mighty_Russia
Avangard is the world’s first hypersonic nuclear capable missile . It’s designed to be carried as a MIRV payload by the UR-100UTTKh, RS-26 Rubezh and RS-28 Sarmat super heavy ICBM. Avangard can presumably reach speeds up to Mach 27 and can be used to deliver nuclear and conventional payloads. It’s designed to sit atop an ICBM and, once launched, it uses aerodynamic forces to sail on top of the atmosphere. Russia deployed its first unit recently.
The system is currently mostly classified but here is what we an deduce so far. The Avangard has a range of over 6000 km, weighs approximately 2000 kg, and can carry a nuclear or conventional payload.7 One TASS report said that the Avangard’s nuclear warhead is “more than 2 megatons in TNT equivalent.”