Description
Trezor Safe 3, Safe 5, and Safe 7 firmware contains a confirmation-binding flaw in the Ethereum sign_tx / sign_tx_eip1559 flow. For contract interactions, the device confirms only the initial calldata chunk while the signature commits to the full streamed calldata. An attacker could present calldata to a victim then supply a different tail that changes the signed transaction. Fixed in 70c9b0c.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Trezor | Safe 3 | < 70c9b0c | 70c9b0c |
| Trezor | Safe 7 | < 70c9b0c | 70c9b0c |
| Trezor | Safe 5 | < 70c9b0c | 70c9b0c |
Advisories 1
- VA-26-202-02 Trezor Safe improper security check in on-device display CISA ICS & IT advisories · Jul 21, 2026