`@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)

published 2026-09-24 45 d ago modified 2026-09-30 39 d ago also GHSA-36f9-7rg5-cpf8 , EUVD-2026-86301

cvss: 8.7; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

`@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

Patch / fix

fixed in 3 links 4

npm @bsv/wallet-toolbox 2.4.0
npm @bsv/wallet-toolbox-client 2.4.0
npm @bsv/wallet-toolbox-mobile 2.4.0

github.com/bsv-blockchain/ts-stack@3a11f61 commit
github.com/bsv-blockchain/ts-stack@5492cab commit
github.com/bsv-blockchain/ts-stack@5ee6039 commit
github.com/bsv-blockchain/wallet-toolbox@ca651b0 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 41 d ago (2026-09-28)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/bsv-blockchain/ts-stack/security/advisories/GHSA-36f9-7rg5-cpf8 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	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
CNA	4.0	8.7	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem	package	affected	fixed in
npm	@bsv/wallet-toolbox	>=1.1.47, <2.4.0	2.4.0
npm	@bsv/wallet-toolbox-client	>=1.1.47, <2.4.0	2.4.0
npm	@bsv/wallet-toolbox-mobile	>=1.3.21, <2.4.0	2.4.0

Affected products

bsv-blockchain @bsv/wallet-toolbox
bsv-blockchain @bsv/wallet-toolbox-client
bsv-blockchain @bsv/wallet-toolbox-mobile

Classification

Weakness

CWE-1288 Improper Validation of Consistency within Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary