Is suffered a common noun

No, the Word 'suffered' is a verb, the past participle, past tense of the verb to suffer.

The past participle of the verb also functions as an adjective.

Examples:

The driver suffered minor injuries. (verb)

He believed that his suffered sleights were intentional. (adjective)

The noun forms for the verb to suffer are sufferer, sufferance, and the gerund, suffering.