Current state

PRISM has not been audited. No security audit has been performed, scoped or commissioned. Nothing is deployed to mainnet.
The tranche mechanics run on Solana devnet only. There is no production deployment to attack and no investor capital at risk, because no pool has been funded.

What is planned

A scoped security audit by a named firm is part of M3, alongside an issuing entity with a securities opinion. Done when: the audit report is published with commit hashes, and the originator and structure are named publicly. Publishing the repository and the deployed addresses comes earlier, at M1.

What an audit will and will not do

Smart contracts can have bugs. An audit reduces this risk. It does not remove it.
An audit checks the code against its intent. It does not check whether the intent is right, and it says nothing about the risks that live outside the contracts:

Where security is structural rather than cryptographic

Several protections in PRISM are checks in code rather than covenants in a document — the first-loss floor, the ratio caps, the transfer allowlist, repayment routing. Those cannot be argued with, which is the point. See contract mechanics in version one. The controls that matter most, though, straddle the code boundary. Controlled collections are enforced by contract on-chain and by a trustee off-chain, and only one of those halves is cryptographic. See the honest limit.