I recently read that, if the mass of a charged black hole is small (compared to its squared charge times some constant), than there is no event horizon, but there is still a (naked) singularity. My doubt is the following:

The presence of a singularity means that the curvature diverges; in other words, gravity tends to infinity as we approch the central mass. So, as we approch the mass, gravity grows and grows unlimitlessly so, at a certain distance, it should become so strong that the escape velocity would be $>c$ (hence, at that distance, we would have an horizon).

What mechanism prevents the formation of an event horizon in the presence of a (relatively small) charged mass?