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Circle freezes Zama's cUSDC wrapper for $12.6M on TRO from federal court

A U.S. federal TRO in Newton AC/DC Fund v. Ermilov forced Circle to blacklist Zama's cUSDC contract at 01:08 UTC on May 30, 2026, locking 12.6M USDC.

by 5 min read
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Circle blacklisted the Ethereum smart contract behind Zama's Confidential USDC wrapper (cUSDC) at 01:08 UTC on May 30, 2026, locking roughly 12.6 million USDC for every holder of the wrapped token. The action was executed against the contract address Etherscan labels Zama: cUSDC Token — 0xe978F22157048E5DB8E5d07971376e86671672B2 — under a temporary restraining order issued the day before by U.S. District Judge P. Casey Pitts in Newton AC/DC Fund LP v. Maxim Ermilov.

What happened

The TRO directs Circle, as USDC issuer, to freeze assets traceable to a disputed transfer that the plaintiff alleges Ermilov, founder of Overnight Finance, misappropriated from the fund's treasury — a claimed loss above $15 million. On-chain investigator ZachXBT flagged that a wallet tied to Overnight Finance treasury operations, 0xf7Fcc767dE537953b3519D4b3097A24A6dFE1c84, deposited approximately 12.4 million USDC into the Zama wrapper on May 11, 2026, then minted cUSDC against it.

Because Zama's ConfidentialWrapperV2 is a pooled wrapper rather than a per-user vault, blacklisting the wrapper contract itself froze every cUSDC holder's claim on the underlying USDC, regardless of whether they had any tie to the disputed deposit. The contract had been live for roughly 154 days when the freeze hit.

Zama founder Rand Hindi said in a public post that the team received no advance notice from Circle or the court, attributed the underlying issue to the Overnight Finance deposit rather than the protocol itself, and credited ZachXBT for surfacing the link. Zama subsequently paused its cUSDC, cUSDT and cWETH wrappers pending the June 1 hearing.

Mechanism — wrapper-level blacklisting

Circle's USDC contract enforces a Blacklisted(address) flag at the ERC-20 transfer hook. When the flagged address is a per-user wallet, only that wallet is locked out; the rest of the float keeps moving. When the flagged address is itself a pooled contract holding USDC for many users (a wrapper, an AMM, a bridge), the freeze applies to the contract's balance — every depositor with a claim on that balance is locked alongside.

Zama's wrapper takes USDC in, mints an equivalent quantity of cUSDC under FHE-encrypted balances, and is meant to release USDC back on burn. Once the wrapper is on Circle's blacklist, the burn-side transfer to a withdrawing user reverts. Confidential balances are still accurate inside the wrapper; the USDC simply cannot leave.

Impact

  • All cUSDC holders are unable to redeem until the contract is unblacklisted or Zama migrates the float to a fresh wrapper outside the flagged address.
  • Zama has paused the related cUSDT and cWETH wrappers as a precaution, even though those are not subject to the Circle blacklist.
  • Per ZachXBT's trace, more than 99% of the USDC inside the wrapper at the time of the freeze originated from the single disputed deposit — which is the legal hook that allowed the plaintiff to argue the entire wrapper balance is traceable property.
  • The wider stablecoin precedent: a U.S. civil TRO has now been used to freeze a privacy-preserving DeFi wrapper contract, not just a named bad-actor wallet. Every wrapper, AMM pool and bridge that aggregates USDC sits inside the same blast radius.

What to watch

  1. The June 1 hearing. Zama says it will try to isolate the flagged deposit so the blacklist can be lifted from the wrapper itself; an alternative path is a narrower court order that targets a synthetic per-user accounting rather than the pooled address.
  2. Circle's standard for wrapper-level action. Whether Circle publishes a policy clarifying when it will blacklist pooled contracts as opposed to end-user wallets, after pushback from Zama and others arguing the action commingles innocent users with the defendant.
  3. Other FHE / mixer-adjacent contracts. Any pooled, privacy-preserving wrapper holding USDC — Aztec-style shields, confidential treasury wrappers, RWA privacy layers — now has a documented precedent against it. Operators of those contracts will need to decide whether to keep USDC at all or to swap to fully decentralised stablecoins.

Context

This is not the first time Circle has acted on a court or law-enforcement order — OFAC's Tornado Cash designation in August 2022 triggered the blacklisting of dozens of addresses associated with the mixer, and Circle has executed prior TRO-based freezes against named wallets. What is new is the target: a smart contract that holds funds for many unrelated users under encrypted balances, frozen on the theory that the entire pooled balance is traceable to a single disputed deposit.

The case lands in the same pattern as the StablR multisig incident this month: a regulated stablecoin issuer's compliance machinery operating exactly as designed, and the downstream blast radius hitting holders who had no role in the underlying dispute. For DeFi teams building on permissioned stablecoins, the operational lesson is concrete — a pooled wrapper inherits the worst-case freeze risk of any single deposit it accepts.

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