Incident case

Rainbow Bridge May 2022 fabricated-block attack attempt

An attacker attempted to submit a fabricated NEAR block to the Rainbow Bridge light client on Ethereum. A watchdog challenged the submission before funds could be released, and no bridge or user funds were reported lost.

reviewedcurrent

Incident facts

Incident title
Rainbow Bridge May 2022 fabricated-block attack attempt
Bridge
Rainbow Bridge
Incident date
2022-05-01
Incident type
Attempted Exploit
Major incident
Yes
Affected chains
Ethereum, NEAR
Affected assets
ETH, Unknown
Attack category
Fabricated Light Client Block
Reported loss
No user-fund loss reported
Amount confidence
High
Loss amount basis
Incident Reporting Based On The Aurora Labs CEO'S Public Account
Recovery
Not Required
Reimbursement
Not Applicable
Restart
Not Interrupted
Current outcome
Attack Thwarted
Postmortem
Partial
Resolution
Final outcome known
Last reviewed
2026-06-15
Last verified
2026-06-15

Amount and valuation

The attempted fabricated-block submission was challenged before funds were released. The attacker reportedly lost a 2.5 ETH bond.

The attacker's forfeited 2.5 ETH bond is not bridge or user loss.

Timeline events

  • May fabricated-block attempt challenged2022-05-01

    A watchdog challenged a fabricated NEAR block before funds could be released; the attacker forfeited a 2.5 ETH bond.

    Fabricated Block ChallengedHigh

    The bond loss belongs to the attacker, not users or bridge reserves.

Evidence records

Source tiers describe evidence authority, not certainty for every claim. Tier 1 is the strongest source class; Tier 2 and Tier 3 provide progressively more secondary or supporting context. Source notes define what each record actually supports.

Known unknowns

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