BIP-143 in the Bitcoin protocol specification mishandles the signing of a Segwit transaction, which allows attackers to trick a user into m…

published 2020-06-16 6y ago modified 2026-06-17 4mo ago also EUVD-2020-6354

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

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.

Patch / fix

fixed in 2

satoshilabs trezor_model_t_firmware 2.3.1
satoshilabs trezor_one_firmware 1.9.1

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Exploit prediction

0.86% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness

CWE-347 Improper Verification of Cryptographic Signature

References

blog.trezor.io /details-of-firmware-updates-for-trezor-one-version-1-9-1-and-trezor-model-t-version-2-3-1-1eba8f60f2dd
third-party-advisory

Sources

CVE List CVE-2020-14199
NVD CVE-2020-14199

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