The International Association of Athletics Federations argued that the Russian Anti-Doping Agency (RUSADA) had incorrectly applied the applicable anti-doping rules adopted by the IAAF to implement the provision of the World Anti-Doping Code with respect to the disqualification of competitive results.
The IAAF challenged the "selective" disqualification of results of Sergey Bakulin, Valeriy Borchin, Vladimir Kanaikin, Olga Kaniskina, Sergey Kirdyapkin and Yuliya Zaripova.
"In each case, the appeal filed by the IAAF has been upheld and the decision issued by the Disciplinary Anti-Doping Committee of the Russian Anti-Doping Agency for each athlete has been modified," CAS said in a statement.
"The CAS is unable to comment on the corrections in the various rankings which may be affected by the present decision and the possible re-allocation of medals, titles, awards or prizes, as this is a matter for IAAF to determine," CAS said.
Russian athletes are serving an indefinite ban imposed by the IAAF after a bombshell WADA report in November uncovered state-sponsored doping and widespread corruption at the heart of Russian track and field.
Russia is now in a race to get its house in order before an IAAF Council meeting in May which will likely decide whether Russian athletes will be allowed to compete at the Rio Olympic Games in August.