A multimeric protein complex that acts as an endosomal tethering complex (CORVET = class C core vacuole/endosome tethering) by cooperating with Rab GTPases to capture endosomal vesicles and trap them prior to the action of SNAREs; the complex is involved in endo-lysosomal biogenesis and required for transport between endosome and vacuole. The Saccharomyces cerevisiae complex contains Vps8p, Vps3p, Pep5p, Vps16p, Pep3p, and Vps33p.