TLDR
- Wanchain’s Cardano-BNB bridge was reportedly exploited for 515 million NIGHT.
- The drained NIGHT tokens were worth roughly $9 million during the incident.
- BlockSec pointed to a possible signature reuse flaw in the validator.
- Midnight Foundation said its core network and validators remain secure.
- NIGHT dropped more than 30% as large token sales hit the market.
NIGHT fell sharply after a reported Wanchain Cardano-BNB bridge exploit drained about 515 million NIGHT, worth roughly $9 million, from the bridge treasury.
Wanchain Bridge Exploit Hits NIGHT Treasury
Blockchain security firm BlockSec’s Phalcon reported that Wanchain’s Cardano bridge was attacked, with about 515 million NIGHT removed from the bridge treasury. NIGHT is the native token of Midnight, a privacy-focused blockchain project linked to the Cardano ecosystem.
The reported exploit affected the Wanchain Cardano-BNB Chain bridge, which supports cross-chain transfers of NIGHT. Wanchain had launched cross-chain NIGHT support between Cardano and BNB Chain in December 2025.
BlockSec said its early review points to a possible flaw in the bridge’s TreasuryCheck validator. The firm described the issue as a non-injective signed-message encoding problem that may have allowed signature reuse.
The security firm said the signed message was built by joining 14 variable-length redeemer fields without separators or length markers. That design could allow different data fields to produce the same message hash.
BlockSec Points to Signature Reuse Risk
BlockSec said the flaw may have allowed an attacker to reuse a valid signature for a different transaction. The firm reached its initial view after reviewing the on-chain Plutus V2 code and the exploit transaction redeemer.
The firm noted that the contract included Cardano’s SerialiseData function. However, BlockSec said the function was not used in the signature-hash construction path.
Wanchain @wanchain_org Cardano bridge was reportedly being attacked, with ~515M $NIGHT drained from the bridge Treasury.
Our initial investigation suggests that the root cause seems to be a non-injective signed-message encoding in the TreasuryCheck validator. The signed message… https://t.co/bnWEnw3Dxc pic.twitter.com/PQFAN6lRn9
— BlockSec Phalcon (@Phalcon_xyz) July 21, 2026
BlockSec said using structured encoding could have prevented this type of field-splitting issue. The firm added that clear field boundaries would stop different data sets from creating the same signed message.
The findings remain preliminary, and Wanchain had not released a full technical postmortem at the time of reporting. Wanchain also issued a security notice regarding the Cardano-BNB Chain bridge.
Midnight Says Core Network Remains Secure
The Midnight Foundation said the incident was isolated to Wanchain’s bridge infrastructure. The group stated,
“The incident is isolated to the Wanchain Cardano–BNB bridge and does not involve the Midnight Network itself.”
The foundation added that Midnight’s protocol, validator network, consensus, and core infrastructure remain secure. It also said the incident affected cross-chain transfers rather than the NIGHT asset or Midnight blockchain.
Midnight said it remains in contact with Wanchain as the investigation continues. The foundation added that current findings do not change the security or operational status of the Midnight network.
The distinction matters because bridge assets can face separate risks from the native blockchain. In this case, the reported issue centered on third-party bridge infrastructure, not Midnight’s core protocol.
NIGHT Selling Triggers Sharp Price Drop
On-chain investigators reported that 515.2 million NIGHT moved from a Wanchain bridge contract in four transfers. The transfers included about 203 million, 129.6 million, 120.4 million, and 62.1 million NIGHT.
Those transfers reportedly reached the same wallet between 14:46 UTC and 14:55 UTC on July 20. Analysts also suggested two wallets involved in later transfers may have been controlled by the same entity.
One wallet reportedly sold about 300 million NIGHT across decentralized exchanges. Confirmed swaps included 217.7 million NIGHT for about 24.02 million ADA and 87.88 million NIGHT for about 1.44 million USDCx.
Source: CoinMarketCap
NIGHT fell more than 30% after the incident, trading near $0.0174 at press time. The token had earlier reached an intraday high of $0.02689 before dropping to $0.01582 during the sell-off.
