Executed Contract + addendum not signed

If you closed on a property and the sellers never actually signed the contract, that's a significant legal issue that your agent calling it "an executed contract, nothing to worry about" doesn't resolve. An executed contract means all parties have signed. If the seller's signature is missing and only a date is on the signature line, the contract may not be fully executed depending on your state's laws. Whether this invalidates the closing, gives you recourse against the seller, or creates liability for the agent or title company are all legal questions that need an attorney's review. You need a real estate litigation attorney, not your agent's opinion. Bring the unsigned contract, the addendums that weren't provided to the lender, evidence of the fraud and non-disclosure you're alleging, and all closing documents. The attorney can evaluate whether the closing is legally valid, whether you have claims against the seller for fraud and non-disclosure, and whether the agent or title company bears any liability for not catching the signature issue. Do not rely on your agent's reassurance. They have a personal interest in this not becoming a bigger problem. Get independent legal advice immediately.

An executed contract means all required parties have signed. If an addendum is unsigned, it’s not valid until all parties agree in writing. Never rely on verbal changes—make sure every term is documented and signed to protect both buyer and seller.

If all parties signed and fully executed closing documents it may be too late however the best thing to do is reach out to a Real Estate/Title Attorney.