Vulnerability · Published Sep 24, 2026 · Assigned by GitHub_M
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
In plain English
A high-severity security flaw in @bsv/wallet-toolbox from bsv-blockchain. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @bsv/wallet-toolbox | 2.4.0 | GHSA-36f9-7rg5-cpf8 |
| npm | @bsv/wallet-toolbox-client | 2.4.0 | GHSA-36f9-7rg5-cpf8 |
| npm | @bsv/wallet-toolbox-mobile | 2.4.0 | GHSA-36f9-7rg5-cpf8 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| bsv-blockchain | @bsv/wallet-toolbox | >= 1.1.47, < 2.4.0 |
| bsv-blockchain | @bsv/wallet-toolbox-client | >= 1.1.47, < 2.4.0 |
| bsv-blockchain | @bsv/wallet-toolbox-mobile | >= 1.3.21, < 2.4.0 |
Weakness: CWE-1288 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/bsv-blockchain/ts-stack/security/advisories/GHSA-36f9-7rg5-cpf8 x_refsource_CONFIRM
- https://github.com/bsv-blockchain/ts-stack/commit/3a11f6111919245a3090e9f3895cfc4f21a80d28 x_refsource_MISC
- https://github.com/bsv-blockchain/ts-stack/commit/5492cabbef4ddc7f60cc49cdf5d8c74ed2e5d949 x_refsource_MISC
- https://github.com/bsv-blockchain/ts-stack/commit/5ee60395e78e8b822d9a78efeacc6039c249819b x_refsource_MISC
- https://github.com/bsv-blockchain/wallet-toolbox/commit/ca651b067c0238cd8b1ddd3af225daa503857a07 x_refsource_MISC