A machine found the bug and set the clock: Ledger disputes TestMachine's timeline

The verification problem here is structural rather than rhetorical. Ledger can push Ethereum app updates through the device's own app store without cutting a matching tagged release on GitHub ^[13]. So the newest public tag sitting at version 1.22.1, dated May 27, 2026, with one listed change about instability in APDU communication handling, is not evidence that a patch was never shipped ^[11]. What it does establish is arithmetic: 88 days separate that tag from the Aug. 23 statement that a fix had gone out two weeks earlier ^[16], and no August tag names the substitution issue at all ^[12]. Ledger has also published no technical advisory, no affected-version list and no patched release identifier, leaving "keep firmware and apps updated" as the entire instruction set ^[1]. That guidance cannot be checked, which is the same thing as saying users cannot check themselves.

The defect itself is a trust-boundary race. TestMachine describes a malicious application sending a competing command while the user is still reading the legitimate transaction, so the screen shows one thing while another is queued for signature ^[4]. The example the researchers offered is a narrow transaction swapped for a broad token approval ^[5]. Clear signing exists precisely so the amounts, addresses and contract actions a user approves are rendered on the device instead of the paired software ^[3], so a display that can be desynchronised from the payload removes the feature's only reason to exist.

The disclosure fight is where the precedent sits. TestMachine says its scanner Azimuth found and validated the flaw during an autonomous scan on a Ledger Flex ^[6], and that the company shared and verified the finding with Ledger but declined a bounty ^[8]. Declining the bounty is the load-bearing detail, because bounty terms are the standard instrument vendors use to control publication timing. Guillemet's account is that the bounty program was contacted only after the fix shipped, and that the vulnerability was never discussed with the bounty team beforehand ^[9]. His counter-claim is that Ledger Donjon had already found the same problem using an AI-powered vulnerability research system of its own ^[19]. Neither sequence has been independently confirmed ^[10]. Both sides, notably, credit a machine with the discovery; what they disagree about is scheduling.

For an owner, the practical residue is small and awkward. The patched app is described as available through Ledger Live, but updating the desktop or mobile interface may leave the stale application installed on the hardware, which has to be updated from the device's own app store ^[15]. No theft through this specific flaw has been independently verified ^[2].