CVE-2026-56744

`@bsv/wallet-toolbox` / `-client` / `-mobile` don't verify storage-supplied recipient output scripts against caller-requested outputs in createAction (can redirect payments when using remote storage)

HIGH
8.7
CVSS Score
Published: September 24, 2026 at 04:56 PM UTC
Updated: September 30, 2026 at 07:57 PM UTC
3 products affected across 1 vendorWallet Toolbox ClientWallet Toolbox MobileWallet Toolbox

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Severity
HIGH8.7
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

`@bsv/wallet-toolbox` provides BRC-100 wallet signing and storage components, while `@bsv/wallet-toolbox-client` and `@bsv/wallet-toolbox-mobile` provide client-focused distributions for standard and mobile applications using wallet storage services. A vulnerability in these packages causes transactions created through a remote `StorageClient` to trust output locking scripts returned by the storage provider without verifying that they match the outputs requested by the caller. A malicious or compromised storage provider can substitute a recipient script or inject an additional output, causing the wallet to sign and broadcast a transaction that redirects funds while the application and user interface continue to display the intended recipient. Source and npm publication history indicate that stable versions `@bsv/wallet-toolbox` and `@bsv/wallet-toolbox-client` from 1.1.47 through 2.3.3, and `@bsv/wallet-toolbox-mobile` from its initial 1.3.21 release through 2.3.3, are affected. All three packages are patched in version 2.4.0. Applications unable to upgrade should avoid remote `StorageClient` providers, use local storage, or independently verify every transaction output’s locking script and value against the original request before signing

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.0
Affected range stops below 2.4.0, so it looks safe — our inference, not a vendor statement
v < 2.4.0
Affected range stops below 2.4.0, so it looks safe — our inference, not a vendor statement
v < 2.4.0
Affected range stops below 2.4.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-1288

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