Overview
- Ledger’s internal Donjon security team deployed a fix in the Ethereum app version 1.22.2 released on Aug. 12 that the company says addressed the flaw before outside researchers went public.
- The bug was an APDU command race condition in clear signing flows where a second host command could replace the transaction held for user review, letting a device show one action while signing a different one.
- Security researcher TestMachine publicly disclosed the issue between Aug. 21 and Aug. 23 and said it validated the behavior on a Ledger Flex and noted shared code could affect Nano X, Nano S Plus, Stax, and Apex models.
- Ledger’s public code changes add checks that refuse a new signing session during an active review and reject approval callbacks when the signing state no longer matches, and users are advised to update firmware and install Ethereum app 1.22.2 or later.
- No confirmed in‑the‑wild exploit or stolen funds have been tied to this specific flaw so far but the case highlights limits of clear signing, growing use of AI in vulnerability discovery, and calls for clearer public advisories and standards.