Taiko Bridge June 2026 forged proof/state exploit

Timeline events

• Taiko recollateralized bridge and reviewed fixes2026-06

  Taiko closed the attack path, restored the pre-attack state, recollateralized the bridge 1:1 in kind, and reviewed fixes with independent specialists before reopening. This restoration is separate from attacker-fund recovery.

  OtherHigh

  Recollateralization and Foundation backfill are not classified as attacker-fund recovery.

• Forged Taiko proof/state enables bridge withdrawals2026-06-21

  An exposed SGX prover signing key and an attestation check that failed to reject debug-enabled enclaves allowed accepted proofs over a fake L2 state. The resulting forged finalized state enabled fraudulent withdrawals through the canonical Bridge and ERC20Vault. Taiko reports about $1.75 million of actual loss.

  Exploit OccurredHigh

  Public description is intentionally non-operational. Taiko states that the ZK proving math and Bridge contracts themselves were not the exploited bug.

• Taiko halted network and bridge operations2026-06-22

  Taiko's Security Council paused the canonical Bridge and ERC20Vault during containment, preventing further withdrawals while additional permissionless proving/proposing paths were disabled and remediation proceeded.

  Bridge PausedHigh

  Pause is first-party documented and distinct from the later July 2 reopening.

• Bridge withdrawals suspended2026-06-22

  Taiko warned that bridge withdrawals were not secure during containment and suspended the affected first-party paths.

  Transfers SuspendedHigh

• Taiko reports about $1.75 million of actual withdrawals2026-06-22

  Taiko's postmortem reports about $1.75 million of actual successful withdrawals before containment. Larger fraudulent claims that never paid are excluded.

  Funds LostHigh

• Taiko Bridge reopened2026-07-02

  After remediation, state restoration and 1:1 recollateralization, Taiko reopened the Bridge and ERC20Vault on July 2 under deliberately conservative withdrawal quotas.

  Bridge ReopenedHigh

• Taiko stated all affected users were made whole2026-07-02

  Taiko states that the Foundation and Taiko Labs covered the complete shortfall, restored 1:1 backing, and made every affected user whole without waiting for attacker-fund recovery.

  Reimbursement CompletedHigh

  Completed user backfill is distinct from still-partial attacker-fund recovery.

• Conservative withdrawal quotas retained2026-07-02

  Taiko retained temporary withdrawal quotas as a post-reopening safeguard.

  OtherHigh

  The safeguard does not by itself establish current limited status after later active verification.

Evidence records

• Taiko incident and containment statement
  Taiko · Tier 1 · High reliability · primary · 2026-06-22
  Claim scope: Incident Case

  Primary source for verification compromise, bridge withdrawals, halt, and approximate USD 1.7 million estimate.

• Taiko bridge reopening and make-whole statement
  Taiko · Tier 1 · High reliability · primary · 2026-07-02
  Claim scope: Reimbursement

  Primary source for restored backing, reopening, all users made whole, and temporary quotas.

• Taiko confirms exploit and halts block production
  The Block · Tier 2 · High reliability · secondary · 2026-06-22
  Claim scope: Incident Case

  Independent contemporaneous incident context.

• Taiko reopens bridge after USD 1.7M exploit
  Crypto Economy · Tier 3 · Medium reliability · secondary · 2026-07-02
  Claim scope: Restart

  Secondary reopening and make-whole context.

• Taiko incident and containment statement
  Taiko · Tier 1 · High reliability · primary · 2026-06-22
  Claim scope: Shutdown

  Event-scoped duplicate supporting suspension of Taiko bridge withdrawals during containment.

• Taiko incident and containment statement
  Taiko · Tier 1 · High reliability · primary · 2026-06-22
  Claim scope: Amount

  Event-scoped duplicate supporting Taiko's approximate USD 1.7 million loss estimate before containment.

• Taiko bridge reopening and make-whole statement
  Taiko · Tier 1 · High reliability · primary · 2026-07-02
  Claim scope: Restart

  Event-scoped duplicate supporting restored backing, reviewed fixes, and the reopening boundary.

• Taiko bridge reopening and make-whole statement
  Taiko · Tier 1 · High reliability · primary · 2026-07-02
  Claim scope: Status

  Event-scoped duplicate supporting temporary conservative withdrawal quotas after reopening.

• Taiko incident and containment statement
  Taiko · Tier 1 · High reliability · primary · 2026-06-22
  Claim scope: Incident Case

  Event-scoped primary copy supporting fraudulent Taiko bridge-message acceptance, affected assets, and immediate containment.

• Taiko bridge reopening and make-whole statement
  Taiko · Tier 1 · High reliability · primary · 2026-07-02
  Claim scope: Reimbursement

  Event-scoped primary copy supporting restoration of the Taiko network and bridge, reopening with conservative withdrawal quotas, and the make-whole commitment.

• Taiko Security Incident: A Postmortem and Next Steps
  Taiko Labs · Tier 1 · High reliability · primary · 2026-07
  Claim scope: Incident Case

  Core first-party incident authority for the forged proof/state mechanism, approximate $1.75M actual loss, itemized successful withdrawals, partial attacker-fund recovery, complete user backfill, remediation and July 2 reopening. The reviewed page does not expose a reliable day-level publication date, so BIR preserves only month precision.

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.