Can mumps cause a bad taste in your mouth?

Salivary glands. A symptom of mumps is infection and swelling of the main salivary glands(parotids). It would be reasonable to assume this could alter taste.
Yes. Mumps infects the salivary gland in the cheeks, the parotid gland. Salivary infections can cause a bad taste . One general treatment is to suck on lemon drops to increase secretion form the salivary gland to promote clearing of the infection.