{
  "id": "ankr-bridge-forged-receipts",
  "url": "https://ohshit.app/incidents/ankr-bridge-forged-receipts/",
  "title": "Forged receipts unlock assets from Ankr’s Ethereum bridge",
  "level": 4,
  "level_name": "septic-tank-blew",
  "date": "2026-11-09",
  "date_is_approximate": false,
  "updated": null,
  "tags": [
    "Ankr",
    "bridge",
    "Ethereum"
  ],
  "ecosystems": [],
  "summary": "SlowMist reports five forged receipts used valid bridge signatures and referenced one earlier Optimism deposit. The Ethereum contract paid out five tokens. SlowMist estimates about $304,500. How the signatures were obtained remains under investigation.",
  "splash": "Ankr’s Ethereum cross-chain bridge escrow and integrations relying on that withdrawal path.",
  "wipe": "Pause affected routes where you control them, preserve signer and bridge records, and verify withdrawals against source-chain events.",
  "in_the_wild": "yes",
  "source_exception": null,
  "cves": [],
  "fixed": [],
  "checklist": [
    {
      "title": "Contain bridge routes and reconcile source events",
      "hint": "If you operate an affected route, suspend or isolate withdrawals you control. Preserve relayer, signer and contract logs. Match each receipt’s recipient, token, amount and unique source event before resuming. Investigate how the signatures were produced and rotate keys if compromise is established."
    },
    {
      "title": "Review the published transaction and address records",
      "hint": "OAK lists 12 traced transfers plus the source event and related addresses. Compare the exact addresses 0x9A88Dd45AE846A979705c9cFdfD0f229e592D703, 0x119D250b82C1cf5345dF5912EFb4B1a4107a1Aa6, 0xc437DF90B37C1db6657339E31BfE54627f0e7181, 0x881d40237659c251811cec9c364ef91dc08d300c, 0x92b2a947551d780f94dda2ef7ec566accdbd796d, 0xd90e2f925da726b50c4ed8d0fb90ad053324f31b, 0x8290333cef9e6d528dd5618fb97a76f268f3edd4, 0x9846c1f06d2f0e7c4678aeea56eb826efe41bb9a. Use the transaction hashes below. OAK identifies 0x92bb1f958a8aeb971227fba643b18cee5abd796d as a lookalike used in spoofed zero-value events. Shared routers can appear in legitimate activity and a match alone does not establish compromise."
    },
    {
      "title": "Verify operator guidance before bridging",
      "hint": "Check Ankr’s official channels before submitting or retrying a transfer on the affected route. Preserve existing transaction hashes and verify status with the operator. Ignore unsolicited refund links."
    }
  ],
  "sources": [
    {
      "name": "SlowMist original technical alert, public copy",
      "url": "https://teapawt.org/SlowMist_Team/status/2119720284093890615",
      "says": "Describes the forged receipts, valid signatures, reused source transaction and estimated amount.",
      "primary": true
    },
    {
      "name": "OAK original transaction trace",
      "url": "https://onchainattack.org/document/examples/2026-11-ankr-ethereum-bridge-forged-signed-receipts-withdraw/",
      "says": "Corroborates five Ethereum withdrawals and documents evidence limits.",
      "primary": true
    }
  ],
  "headline": null,
  "one_liner": null,
  "in_the_wild_note": "SlowMist and OAK report five withdrawals. Signing-key exposure remains unconfirmed.",
  "mitigation": null,
  "timeline": [
    {
      "date": "Nov 9, 08:09 UTC",
      "title": "Ethereum bridge begins paying the forged receipts",
      "body": "OAK’s trace shows five withdrawals to a single recipient between 08:09:35 and 08:11:59 UTC."
    },
    {
      "date": "Nov 9, 09:14 UTC",
      "title": "SlowMist publishes its initial analysis",
      "body": "The researchers estimate about $304,500 and identify the reused Optimism transaction and signed receipts."
    },
    {
      "date": "Nov 10, 2026",
      "title": "OAK traces the Ethereum leg",
      "body": "Its independent transaction trace corroborates the five releases."
    }
  ],
  "body_markdown": "SlowMist’s [original alert](https://x.com/SlowMist_Team/status/2119720284093890615) says the bridge accepted five receipts that changed the recipient, token and amount while referring to the same legitimate Optimism transaction. The receipts carried valid consensus signatures. OAK traced withdrawals of ankrETH, ANKR, ankrMATIC, aPOLb and aETHb to one recipient. The dollar figure is SlowMist’s estimate. OAK’s trace provides transaction corroboration and does not establish final net loss or prove signing-key theft. The reviewed material did not establish a vendor remediation, confirmed pause or reimbursement plan.\n\nPublished transaction hashes. The first is the legitimate Optimism source event reused by the forged receipts.\n\n```text\n0x02e805b51beb4ed39e6a66ffcbdf9060cf008b3c3f0e827d0d357dfa115e7d4a\n0x139e3e30b2993b96aec206e168d299d1678cf05a57c58d90593cf6c7b5f6d3e8\n0x7310af5d53e08259915bc3547daf343d188b9c36db8dd6b3ff3b5e70565e88df\n0x90c563360cc343a640721662abe762e9ab9665aee0c22820b1656ff23bcfc891\n0xde2d5b455c0071698fec9c23a9c50f9ecdfd8efa96b4fbb48ed0620bd4c29b5c\n0x91ba1a9c81a1bb67ce7a2779d5b2de54b7aece166f67d9e3a31e29e4e13c2886\n0x46e20d4c8cd43dece94f7a2a890a348fefcb0dc8310279658c8f836e758bdad0\n0x05f3d8109ca5bbc9e4d51697667ba9013dac5a476f1e2c6e695fffdfa2f0368c\n0x560715bdd7f6eb59907395f6c6b519c489c2e7d1a13a22580079866a8c0799a8\n0x393524106e749e57086c5b67e27cdbfabad4b30087dbe85c11e5b11099ff6bf3\n0xfb4288a47f0146a534c17480b9eca017994fa587c25f022b051abb70c8e38e53\n0x604820e86bc0eff1c85f4cbc2a4cc34d0c17f7254903e8623776359a8e042b90\n```"
}