Zentra Finance reported an exploit involving its ctUSD reserve on Citrea Mainnet, estimating losses of approximately $143,000. The incident occurred at 12:59:37 UTC on September 9, 2026, according to the protocol's September 11 post-mortem. Zentra suspended its lending markets while investigating the affected system and tracing the funds, but has not disclosed the vulnerability or attack method, identified the wallet holder or indicated that other reserves were affected. The protocol said the funds were traced to a specific wallet and asked for their return to 0x0A66f2D0c603A6E9C23b64Ea29525B7E6F5609B8, offering a bounty with terms to be negotiated and no legal or investigative action if the assets were returned under agreed conditions. Zentra set September 14, 2026, at 12:00 UTC as the response deadline and said it could pursue technical, onchain and legal measures if there was no response. The lending markets have no announced reopening date. The incident comes amid other DeFi (decentralized finance services built on blockchain networks) security events involving ether.fi's legacy AtomicQueue system and the Symbiosis Bridge, which used different attack mechanisms.