Bridge Incident Registry
Bridge entity

Synapse Protocol

Synapse Protocol provides cross-chain bridging, liquidity, and messaging infrastructure. It is included because a November 2021 bug in the nUSD metapool implementation allowed price manipulation and an attempted extraction of approximately $8.2 million in nUSD, but validators remained offline and did not process the malicious bridge transaction, allowing affected liquidity providers to be made whole.

active reviewed current

Bridge facts

Canonical name
Synapse Protocol
Type
Interoperability Protocol
Status
Active
Confidence
High
Primary chains
Ethereum, Avalanche, BNB Chain, Polygon, Arbitrum, Optimism, Fantom, Unknown
Primary assets
nUSD, USDC, USDT, DAI, ETH, Unknown
Operator
Synapse Protocol
Ecosystem
Synapse
Launch date
2021-08-29
End date
Unknown
Terminal reason
Not applicable / unknown
Last reviewed
2026-06-15
Last verified
2026-06-15

Incident cases

  • Synapse 2021 nUSD metapool exploit2021-11-06

    An attacker manipulated the Avalanche nUSD metapool virtual price by approximately 12.5% through a bug in the Saddle-derived metapool implementation. The attacker attempted to move approximately $8.2 million in nUSD through the bridge while validators were offline; the malicious transaction was not processed and affected liquidity providers were to be made whole.

    ExploitNo ultimate fund loss reported; approximately $8.2 million nUSD protectedUnresolved

Evidence records

Official URL status

Official URL recorded as live: https://bridge.synapseprotocol.com/