During the summer of 2012 (following a change of ownership in Lokomotiv Plovdiv) Venkov signed a contract with CSKA Sofia, but was initially unable to play in official matches for the team due to a transfer prohibition imposed on the "redmen".The ban was lifted in mid September 2012 and Venkov made his official debut on 22 September, in the 0–1 away loss against Ludogorets Razgrad He scored his first goal for CSKA from a header against Slavia Sofia in 0–2 away win.Venkov made his first appearance in The Eternal Derby on 20 October 2012, playing the full 90 minutes of the 1–0 win over Levski Sofia.