The term disvalor is not part of the dictionary of the Royal Spanish Academy (RAE). The concept, however, is used in different contexts and with different scopes.
Disvalor
It is called a devalue to a deviation of a value (an estimable, positive quality). A value can be understood as the midpoint between two extremes: absence and excess. The exaggeration of a value, in this framework, is called disvalue.
Courage, for example, is a value. The lack of it is called cowardice; to exaggeration, recklessness. Recklessness, in short, is a disvalue because it is a distortion of courage.
A disvalue, on the other hand, is a loss that cannot be quantified in economic terms. Suppose a man, by accident, loses his hands. Because a huge amount of tasks that take place on a daily basis require the use of hands, there is no way to estimate, economically, how much the subject in question lost. The individual, therefore, carries a disvalue.
It can also be considered as disvalue to the detriment that suffers a value. Legal security, to mention a case, is a value based on trust in the laws that protect rights. When legal security is respected, the person can count on tranquility and certainty in their actions. On the other hand, certain socio-political decisions can lead to the correlative disvalue that causes unrest and uncertainty among citizens. This is because, as legal certainty is not guaranteed, people may be left unprotected.