Transaction manipulation via unconfirmed streamed calldata
Published Jul 21, 2026 · Updated Jul 21, 2026
Confirmation-binding failure in Trezor Safe 3, Safe 5, and Safe 7 firmware before 70c9b0c allows attackers to alter signed transactions. The sign_tx and sign_tx_eip1559 handlers display only data_initial_chunk but hash every later data_chunk into the signed digest. Exploitation requires a victim to approve the transaction while an attacker controls the streamed tail, enabling unauthorized contract actions without disclosing keys.
Summary
What happened
Confirmation-binding failure in Trezor Safe 3, Safe 5, and Safe 7 firmware before 70c9b0c allows attackers to alter signed transactions. The sign_tx and sign_tx_eip1559 handlers display only data_initial_chunk but hash every later data_chunk into the signed digest. Exploitation requires a victim to approve the transaction while an attacker controls the streamed tail, enabling unauthorized contract actions without disclosing keys.
The record
- CVE
- CVE-2026-65058
- Published
- Jul 21, 2026
- Updated
- Jul 21, 2026
- Vendor
- Trezor
- Product
- Trezor Safe 5
- Classifications
- CWE-358, T1565.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 21, 2026CVE publishedPublication date reported by the CVE source.
- Jul 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <70c9b0c
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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