Ledger Closes a Gap in the Ethereum App: When the Display Shows Something Other Than What You Sign

Anyone who owns a Ledger and uses it to manage Ether or ERC-20 tokens should open Ledger Live and check which version of the Ethereum app is installed on the device. Anything older than 1.22.2 is missing a security fix. That fix closes a flaw which undermined the very promise a hardware wallet is bought for: that the screen shows what the device is about to sign.

The case became public on August 24, 2026, when the security firm TestMachine published its analysis. The fix itself already existed by that point. Between the two dates lies a dispute over who found the flaw first and when Ledger shipped it. For you as an owner, that dispute is secondary. What matters is the version number on your device and the question of which approvals you granted in the past.

Ledger security vulnerability in the Ethereum app: what actually happened

Neither the device firmware nor the custody of the private key was affected. The problem sat in the Ethereum app: the small piece of software you install on the device in addition, for Ether and ERC-20 tokens. It prepares a transaction, displays it to you and collects your confirmation.

In the faulty version, that sequence could be thrown out of order. A malicious web application with access to the connected device could send a second signing command while the first transaction was still on screen awaiting review. The app then swapped the data in memory without bringing up a fresh review screen. The harmless transfer you had just examined remained on the display. Your confirmation, however, applied to the swapped data.

According to the security researchers, the pattern has been demonstrably reproduced on a Ledger Flex. Because the devices largely share the Ethereum app's program code, the Nano X, Nano S Plus, Stax and Apex are also considered potentially vulnerable. Ledger has not disclosed which version of the app first contained the error; the researchers' comparison starts at 1.22.1, the previously tagged version from May 27, 2026.

Clear signing explained: why the display is the real security promise

Clear signing refers to showing the complete transaction data in plain text on the hardware wallet's display before you confirm: recipient address, amount, and in the case of contract calls, the action the contract is meant to perform.

This is the reason such a device makes sense in the first place. Your computer may be compromised, your browser may render a manipulated interface, the website may be a fake. As long as the device in your hand has its own screen, independent of the computer, and shows the real data there, any manipulation becomes visible before you press the button. The private key never leaves the device; it does not need to, because the device signs for itself.

The flaw struck exactly this chain at its weakest point. The key stayed safe, the firmware was untouched, and yet a different consent could end up being given than the one you had read. A device whose display can no longer be read as binding is, on this one point, no better than a software wallet on an infected machine. If you want to revisit the difference between the two designs, you will find it in our software wallet comparison and in the hardware wallet comparison.

Race condition and APDU commands: the technical core of the flaw

A race condition is a bug in which the outcome depends on which of two roughly simultaneous commands gets processed first. Such bugs are treacherous, because the program code looks correct on its own and the sequence runs cleanly in the vast majority of cases. They only surface when someone deliberately engineers the order.

APDU is the command format in which smart cards and hardware wallets talk to the connected computer. Every step of a signature consists of several such commands. The Ethereum app carried a state alongside them, recording which transaction was currently up for review. That state could be overwritten while the review was still running.

WebHID in the browser: why a website talks to your device at all

WebHID is a browser interface that lets a website communicate directly with a connected USB device once you have explicitly granted permission. Without it, a hardware wallet could not be used conveniently inside a decentralised application; with it, the website sits closer to the device than many users realise.

The attack described requires that you have already granted this access to a manipulated or hijacked site and that you initiate a transaction there. It does not work remotely against a device sitting in a drawer. That limits the circle of those affected considerably, though it does not diminish the finding: anyone who works regularly with decentralised exchanges, bridges or staking interfaces grants this access all the time.

Token approval instead of transfer: why unlimited approvals are so dangerous

The damage in a swap of this kind rarely comes from the transfer itself. It comes from what can be slipped in to replace it.

A token approval is the permission granted to a smart contract to dispose of a certain quantity of your tokens in future, without you confirming each individual debit again. Many applications request this permission on an unlimited basis for the sake of convenience. An approval once granted does not expire and remains in force until you explicitly revoke it.

The difference between a transfer and an approval

A transfer costs you exactly the amount you confirm. An unlimited approval costs you, in the worst case, the entire balance of the token concerned, at a moment of the recipient's choosing. That is why swapping a small transfer for a far-reaching approval is the most rewarding attack on a signing path. How attackers collect these approvals in practice is something we set out in our piece on wallet drainers and signature approvals.

Updating the Ethereum app to 1.22.2: the route through Ledger Live

Version 1.22.2 closes the route described with two locks. The app refuses a new signing session while a review is in progress, and it rejects an incoming confirmation if the state no longer matches what was displayed. The version entry sits in the release overview of the Ethereum app at Ledger; the note there lists only fixed security issues as its content, without describing the flaw.

The update itself is unspectacular. You connect the device, open the manager for installed applications in Ledger Live and update the Ethereum app there. Existing balances are unaffected, because the keys are derived from your recovery phrase and do not reside in the app. Removing and reinstalling the app costs you no coins either.

How to identify the installed version

Ledger Live shows the version number for each application in the device manager. If it reads 1.22.2 or higher, the fix is in place. If it reads 1.22.1 or older, it is missing. A glance at the version number of Ledger Live itself is not enough.

Why a firmware update does not update the Ethereum app with it

This is the point at which the case most often goes wrong in practice. Firmware, Ledger Live and the individual coin apps are maintained separately and updated separately. Someone who updates the device firmware and comes away feeling reassured may still have an outdated Ethereum app on the device.

The same separation explains why reports on wallet security so often talk past each other. In the Coldcard case the error lay in the generation of the seed, right down at the foundations, which is why a new seed was needed there. The BitBox vulnerabilities concerned the firmware. Here the error sits one level above that, in a replaceable application, and so an app update is sufficient. Your recovery phrase does not need to be regenerated in this case.

Checking and revoking token approvals: the second step after the update

The update protects future signatures. It does not clear up what was granted in the past. If you have worked with decentralised applications over recent months, it is worth looking at the open approvals on your address.

Block explorers and specialised interfaces list, for a given address, which contracts are allowed to dispose of which tokens. Approvals to contracts you no longer use can be revoked one by one. A revocation is an ordinary transaction and incurs network fees, which is why the clean-up is best done in quiet periods with low fees. If you want to keep an eye on the Ether price while doing so, you will find our assessment in the Ethereum price prediction.

One side effect that hardly anyone thinks about: every revocation appears in your transaction history and generates fees. Those who document their movements cleanly have an easier time at the next tax return; the common tax and portfolio tools read such events in automatically.

The disclosure dispute between Ledger and TestMachine

There are two accounts of the sequence of events, and they do not match. Both are reproduced here as the accounts of the respective party; neither has been independently confirmed.

Ledger's chief technology officer Charles Guillemet stated that the in-house security lab Ledger Donjon had found the error itself, and that the fix was shipped roughly two weeks before publication. TestMachine, he said, only came forward to the bug bounty programme afterwards. He characterised the security firm's statements as generating fear in order to attract attention.

TestMachine counters that its own testing system, named Azimuth, discovered the weakness during an automated run on a Ledger Flex, and that the results were shared with Ledger. At the time of publication, in the firm's view, no fix was available.

The verifiable individual facts sit somewhere in between. The changelog entry for version 1.22.2 carries the date August 12, 2026, the signed tag in the source repository August 13. It only became visible as a published release around August 24, however, at the same time as the security firm's analysis. A user who wanted to check in the meantime whether a fix existed could not find it there. The technical reconstruction of the sequence, including these dates, was assembled by CryptoSlate.

Have funds been lost? What is known about the damage

Based on the information provided so far by both sides, there is no confirmed case in which the flaw was actually exploited. No losses are documented, and reading out private keys was not possible by this route in any event.

That is good news with a caveat that has to be stated alongside it. A signature obtained this way would look on chain like any other voluntary signature. An affected user would only notice the event once tokens later flowed out, and would then probably attribute it to ordinary phishing. The absence of confirmed cases therefore does not allow the conclusion, with any certainty, that there were none. That is an assessment, not a documented statement.

What the case says about hardware wallets and self-custody

It would be the wrong conclusion to turn this episode into a rejection of hardware wallets. The attack required device access already granted and a malicious application, it left the key untouched, and it has been fixed.

The useful conclusion is a different one. A hardware wallet moves trust from the computer to a small device with its own screen, and that device consists of firmware, applications and companion software, all maintained separately. Security at this point is not a state you acquire with the purchase, but an upkeep you perform. That includes keeping applications current, tidying up approvals regularly and, for large holdings, adding a second layer of confirmation. Which class of device suits which holding is something we broke down after the Coldcard case in our piece which hardware wallet now?

Checking the Ledger Ethereum app: what to take away

1. Check the version and update it. Connect the device, open the device manager in Ledger Live and check the Ethereum app. Anything below 1.22.2 needs updating, and a firmware update alone will not do it. Which devices handle this separation in which way is shown in the hardware wallet comparison.
2. Clear out open token approvals. Have your address checked for which contracts may dispose of your tokens, and revoke everything you no longer need. If you conclude in the process that you want a separate address with a small balance for daily use, the software wallet comparison will help with the choice.
3. Document the movements. Revocations and reallocations generate fees and show up in your history. Record them as you go, rather than reconstructing them next spring; the tax and portfolio tools take the import work off your hands.

(As of August 25, 2026. This article is not investment advice. Prices and fee structures change; check the terms with the provider before you buy.)