The Solana Program Security Checklist I Wish I'd Had on Day One

I spent the last two weeks thinking like an attacker. I wrote tests whose only job was to make my own programs fail. I ran a fuzzer across thousands of generated inputs looking for the lamport value nobody would choose by hand. And I rebuilt the missing owner check that was at the center of the $326M Wormhole exploit, in a throwaway program, in a test, so I could watch it work and then watch the one-line fix stop it cold. This checklist is what I would hand to past me on day one of that work. Run it top to bottom before any Anchor program goes to mainnet. Who this is for You are writing Solana programs in Anchor. You understand accounts, PDAs, and CPIs. You have read the Anchor docs. What you do not yet have is a systematic way to check that you have not missed the failure modes that are specific to Solana's runtime, an account model where any account can be passed into any instruction, arithmetic that wraps silently in release builds without protection, and cross-program calls that trust whatever program ID you hand them. This checklist is that systematic check. It is not a substitute for a professional audit on high-value programs. It is the thing you run before you even consider requesting one. The Wormhole anchor Before the list, the story that explains why account validation sits at the top. In February 2022, an attacker drained $326M from the Wormhole bridge. The root cause was a single deprecated function, load_instruction_at — that read a sysvar account's contents without first checking that the account was actually the real instructions sysvar. The attacker passed in a forged account they controlled. The program read it, trusted it, and authorized a mint it should have refused. The fix was a single word: switch to load_instruction_at_checked , which verifies the account's address before reading it. Every item in this checklist traces back to that same principle: never read an account's contents until you have confirmed its identity. The items below are just