The Collaborative International Dictionary of English v.0.48:

Overstate \O`ver*state"\, v. t. [imp. & p. p. Overstated; p.
   pr. & vb. n. Overstating.]
   To state in too strong terms; to exaggerate. --Fuller.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

overstated \overstated\ adj.
   represented as greater than is true or reasonable;
   exaggerated; as, They made overstated accusations of
   corruption.

   Syn: exaggerated, overdone.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

overstated
    adj 1: represented as greater than is true or reasonable; "an
           exaggerated opinion of oneself" [syn: exaggerated,
           overdone, overstated]