We use the conformal bootstrap to study conformal field theories with O(N ) global symmetry in d = 5 and d = 5.95 spacetime dimensions that have a scalar operator φ i transforming as an O(N ) vector. The crossing symmetry of the four-point function of this O(N ) vector operator, along with unitarity assumptions, determine constraints on the scaling dimensions of conformal primary operators in the φ i × φ j OPE. Imposing a lower bound on the second smallest scaling dimension of such an O(N )-singlet conformal primary, and varying the scaling dimension of the lowest one, we obtain an allowed region that exhibits a kink located very close to the interacting O(N )-symmetric CFT conjectured to exist recently by Fei, Giombi, and Klebanov. Under reasonable assumptions on the dimension of the second lowest O(N ) singlet in the φ i × φ j OPE, we observe that this kink disappears in d = 5 for small enough N , suggesting that in this case an interacting O(N ) CFT may cease to exist for N below a certain critical value. *