There may be a violation, but it isn;t a violation of 26 USC 6103.
The law specifies "return information", not "return".
(2) Return informationThe term “return information” means—
(A) a taxpayer’s identity, the nature, source, or amount of his income, payments, receipts, deductions, exemptions, credits, assets, liabilities, net worth, tax liability, tax withheld, deficiencies, overassessments, or tax payments, whether the taxpayer’s return was, is being, or will be examined or subject to other investigation or processing, or any other data, received by, recorded by, prepared by, furnished to, or collected by the Secretary with respect to a return or with respect to the determination of the existence, or possible existence, of liability (or the amount thereof) of any person under this title for any tax, penalty, interest, fine, forfeiture, or other imposition, or offense,
[There's more, but this is the relevant part]
Even though the information might have come from a state return, it's the same information as a federal return.
State returns are a virtual mirror of the Federal return.
In many states-—a COPY of the Federal return MUST be attached to the state return. Both for individuals & companies.