Laser fault injection bypasses firmware checks on Trezor Safe 7's TROPIC01 chip

On 3 June 2026 Ledger Donjon, Tropic Square and Trezor jointly disclosed an attack on TROPIC01, the open-source secure element made by Tropic Square and used in the Trezor Safe 7. Donjon says it decapsulated the chip from the back and used a 1064 nm laser to fault the Ed25519 signature check once during a firmware update and once during boot, which let it run its own firmware on the chip.

Donjon did not extract secrets in its initial testing. Tropic Square then found a separate way to bypass the hardware boundary of the chip’s MAC-and-Destroy mechanism, which Donjon says underpins PIN verification on the Safe 7, and Donjon later found its own route; both have withheld the details. Tropic Square rates the issue medium (CVSS 3.1 score 5.7), says it affects current-silicon TROPIC01 chips and offers a firmware mitigation (disabling maintenance mode). Donjon reports it could force the chip back into maintenance mode with a second fault, keeping the attack practical in under an hour. Tropic Square plans a hardened chip revision in late 2026 and a full technical report in spring 2027.

Trezor states that TROPIC01 is one of three independent security layers, that it does not store the keys to funds or the wallet backup, and that compromising it alone does not give access to the PIN, funds or backup. Trezor says the attack requires disassembly, desoldering, decapsulation and specialised lab equipment, that a full fix cannot be applied remotely, and that it cannot commit to whether or when an updated chip will be available.

Timeline according to Donjon: audit began 23 December 2025, first successful attack 26 January 2026, confidential disclosure to Tropic Square 27 January, and agreement on 7 May to publish on 3 June.