CVE-2020-14199: Satoshilabs Trezor Model T Firmware

Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days.

BIP-143 in the Bitcoin protocol specification mishandles the signing of a Segwit transaction, which allows attackers to trick a user into making two signatures in certain cases, potentially leading to a huge transaction fee. NOTE: this affects all hardware wallets. It was fixed in 1.9.1 for the Trezor One and 2.3.1 for the Trezor Model T.

Affected products

• Satoshilabs Trezor Model T Firmware: before 2.3.1 (fixed in 2.3.1)
• Satoshilabs Trezor One Firmware: before 1.9.1 (fixed in 1.9.1)

Published 2020-06-16. Last modified 2026-06-17.