Weak erase detection and mitigation techniques are provided that detect permanent failures in solid-state storage devices. One exemplary method comprises obtaining an erase fail bits metric for a solid-state storage device; and detecting a permanent failure in at least a portion of the solid-state storage device causing weak erase failure mode by comparing the erase fail bit metric to a predefined fail bits threshold. In at least one embodiment, the method also comprises mitigating for the permanent failure causing the weak erase failure mode for one or more cells of the solid-state storage device. The mitigating for the permanent failure comprises, for example, changing a status of the one or more cells to a defective state and/or a retired state. The detection of the permanent failure causing the weak erase failure mode comprises, for example, detecting the weak erase failure mode without an erase failure.