They are not the same.  

Benghazi was a cover up of how a United States Ambassador was killed and how the Obama administration, including Hillary and the Ambassador to the United Nations at the time came up with 'Talking Points' in the middle of a re-election campaign to minimize the political impact.

"The CIA immediately (and correctly) asserted that it was a terrorist attack, so why did the Obama administration tell the American people that it was a protest in response to an utterly obscure YouTube video that was deemed offensive to Muslims?"

This Sessions situation is, at the very best, a lie by a sitting Senator in a confirmation hearing about speaking with a Russian Ambassador.

The two situations are quite different.