AIKIDO-2026-484607

TL;DR

The Tempo pull-transaction charge verification in src/tempo/server/Charge.ts matches on-chain transfer calls and logs against the expected payment but does not confirm the transfer memo is cryptographically bound to the current server challenge. When the expected transfer has no server-set memo the matcher treats it as allowAnyMemo and accepts any memo, so a signed transaction or transfer whose attribution memo was bound to a different challenge still verifies. An attacker can reuse or replay such a payment against a separate challenge for the same amount, currency, and recipient, bypassing per-challenge payment authorization. The fix adds assertChallengeBoundCallMemo and applies assertChallengeBoundMemo to matched calls and logs so the memo must verify against the current challengeId and realm.