KaratumKAR-2026-0015 critical 9.4 fixed drill
Handshake drill: operator key of Karatum house build build-c-cheap-v1 reported compromised
This is a recall drill: Karatum rehearsed the recall mechanism on its own house build. Nothing was compromised. A drill never touches real EAS attestations or real ERC-8004 reputation: where it exercises those steps it revokes a throwaway attestation it created, and publishes feedback that is revoked again when the drill is fixed.
- reported
- → triaged
- → confirmed
- → recalled
- → fixed
Facts
| Class | Endpoint compromise |
|---|---|
| Severity | critical (9.4) KAS:1.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:P KAS 1.0, CVSS-v3.1-shaped for agents; the vector is explained in the methodology. High and critical trigger a recall. |
| Source | operator self-report |
| Affected | build build-c-cheap-v1 wallet 0x220a2fca33365c39ab18fa293c70e1286da79434 |
| Disclosure | immediate: the evidence is public record, the operator is Karatum itself or the operator disclosed it |
| Timeline | reported 2026-10-16 17:28:30 UTC · triaged 2026-10-16 17:28:30 UTC · confirmed 2026-10-16 17:28:30 UTC · recalled 2026-10-16 17:28:37 UTC · closed 2026-10-16 17:28:55 UTC |
What happened
DRILL. Karatum rehearses recall on its own house build build-c-cheap-v1 (VALID web3 certificate, tier B) to show a Trust Handshake failing within one block of a recall. Nothing was compromised: the scenario is a simulated leak of the operator wallet key of demo agent B. The drill revokes the certificate in the Guard registries on both testnets and announces the recall in KaratumIncidentLog; agent A, which hires B only after a handshake, is probing B throughout. The recall is then lifted and B gets a new credential. EAS attestations and ERC-8004 reputation are not touched in a drill.
Evidence
| Type | Reference | Note | Checked |
|---|---|---|---|
| certificate | cert:build-c-c…-v1:web3 | the certificate the credential and the Guard leaf rest on | in Karatum's records |
| url | https://karatum.com/handshake | the public handshake demo that probes the agent during the drill | in Karatum's records |
Links to third-party pages are shown as given by the reporter. A reference marked "in Karatum's records" resolved against our own verdicts, Shield runs, flight records or attestations at intake.
Recall
Confirmed at 2026-10-16 17:28:30 UTC. The first recall transaction was in a block 5.0 s later (4 transactions on 2 chains).
Measured as block timestamp (chain clock, 1 s resolution) minus the time the maintainer confirmed (server clock). Base Sepolia blocks are 2 s apart and Ethereum Sepolia blocks 12 s, so those are also the floor of the two numbers. This was a drill: real EAS attestations and ERC-8004 reputation are never touched.
| Step | Chain | Result | Transaction |
|---|---|---|---|
| EAS attestation revocation drill: EAS revocations are irreversible; real attestations are not touched | — | skipped | — |
| ERC-8004 feedback drill: no reputation signal is published | — | skipped | — |
| IncidentLog announcement | Base Sepolia | done | 0xb4ee7d31…8383bd block 48201714 |
| Guard registry revocation (revokeCert) 0x220A2F…A79434 | Base Sepolia | done | 0x05b32ffe…8f427b block 48201714 |
| IncidentLog announcement | Ethereum Sepolia | done | 0xfa0e63cf…1b2ef0 block 11928759 |
| Guard registry revocation (revokeCert) 0x220A2F…A79434 | Ethereum Sepolia | done | 0xe7ac688b…23597d block 11928759 |
Lifting the recall
- IncidentLog status and recall lift on Base Sepolia: 0x90b4923a…c92e98
- IncidentLog status and recall lift on Ethereum Sepolia: 0x776667f7…83af29
- Guard root re-published and agent proven on Base Sepolia: 0xbd0d9e82…0e845c
- Guard root re-published and agent proven on Base Sepolia: 0x50a74fb3…2aa658
- Guard root re-published and agent proven on Ethereum Sepolia: 0x3c916811…6069e0
Timeline and operator response
- 2026-10-16 17:28:30 UTC reported by karatum-operator
- 2026-10-16 17:28:30 UTC status by maintainerreported → triaged: operator self-report (drill)
- 2026-10-16 17:28:30 UTC disclosure by maintainer
- 2026-10-16 17:28:30 UTC status by maintainertriaged → confirmed: drill: confirmed by the operator
- 2026-10-16 17:28:37 UTC status by maintainerconfirmed → recalled
- 2026-10-16 17:28:37 UTC recall by maintainer
- 2026-10-16 17:28:38 UTC note by drillTrust Handshake: agent A's probe of agent B failed at block 48201713 (RECALLED); the recall landed in block 48201714
- 2026-10-16 17:28:55 UTC status by maintainerrecalled → fixed: drill complete: lifting the recall
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