While the question limits itself to statutes, it is important to realize that in the United States, a very large share of all theories of legal liability are not codified in statutes. The vast majority of lawsuits are brought based upon common law theories, not to enforce statutory rights. With that in mind, here are some common law theories of liability that might apply.
Under some circumstances, someone might be able to bring an intentional interference with contract or intentional interference with business advantage lawsuit under a tortious interference common law theory.
Most of the elements would be met in these circumstances:
- The existence of a contractual relationship or beneficial business relationship between two parties.
- Knowledge of that relationship by a third party.
- Intent of the third party to induce a party to the relationship to breach the relationship.
- Lack of any privilege on the part of the third party to induce such a breach.
- The contractual relationship is breached.
- Damage to the party against whom the breach occurs.
If you weren't a competitor, there wouldn't be a competitor's privilege, which is the most common defense. Also, this wouldn't apply if the conduct was deemed wrongful for tort purposes, which this conduct might very well be considered to be.
Conceivably, one could also bring a civil conspiracy claim, arguing that you are conspiring with unidentified hackers to do harm to the company impacted. This would be particularly plausible in the case where he published open source software, and would be even more plausible if he somehow profited from the mayhem that revealing the breach caused.
The big question would be whether there would be a First Amendment privilege for otherwise truthful speech about lawfully obtained information, but as noted in another post, the law on that question is muddy.
At a minimum, I can't think of any obvious whistle blower statutes that would apply.
I suspect that it might also be possible to prosecute someone for doing so if the network was a military one and it implicated classified national defense matters (even if you never had actual notice of the fact that it was classified).