Bridge Incident Registry
Incident case

ChainSwap July 10–11, 2021 quota exploit

A logic flaw in ChainSwap's cross-chain quota code allowed non-whitelisted addresses to increase bridge quota and affect 20 bridged assets. ChainSwap reported a combined value of approximately $4 million and took the bridge offline.

reviewedcurrent

Incident facts

Incident title
ChainSwap July 10–11, 2021 quota exploit
Bridge
ChainSwap
Incident date
2021-07-10
Incident type
Exploit
Major incident
Yes
Affected chains
Ethereum, BNB Chain, Unknown
Affected assets
Unknown
Attack category
Smart Contract Bug
Reported loss
Approximately $4 million
Recovery
None
Reimbursement
In Progress
Restart
Reopened
Current outcome
Active After Incident
Resolution
Unresolved
Last reviewed
2026-06-15
Last verified
2026-06-15

Timeline events

  • Second July exploit affected 20 bridged assets2021-07-10

    A quota-logic flaw was exploited across 20 bridged assets, after which ChainSwap took the bridge offline and froze mapping tokens.

    Second Exploit And Bridge ShutdownHigh

  • ASAP token replacement and compensation plan documented2021-07-13

    ChainSwap described issuing a replacement token, using a pre-exploit snapshot, and compensating affected projects and holders after the second exploit.

    Token Replacement And CompensationHigh

  • ChainSwap bridge relaunched2021-08-20

    ChainSwap announced that the bridge was live again after the July incidents and remediation work.

    Bridge RelaunchedHigh

Evidence records

Known unknowns