CVE-2026-40070

bsv-sdk and bsv-wallet persist unverified certifier signatures in acquire_certificate (direct and issuance paths)

HIGH
8.1
CVSS Score
Published: April 9, 2026 at 05:26 PM UTC
Updated: October 26, 2026 at 09:10 PM UTC
1 product affected across 1 vendorBSV Ruby SDK

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Severity
HIGH8.1
Exploit prediction
EPSS 0.1%
SSVC
PoC

Description

BSV Ruby SDK is the Ruby SDK for the BSV blockchain. From 0.3.1 to before 0.8.2, BSV::Wallet::WalletClient#acquire_certificate persists certificate records to storage without verifying the certifier's signature over the certificate contents. In acquisition_protocol: 'direct', the caller supplies all certificate fields (including signature:) and the record is written to storage verbatim. In acquisition_protocol: 'issuance', the client POSTs to a certifier URL and writes whatever signature the response body contains, also without verification. An attacker who can reach either API (or who controls a certifier endpoint targeted by the issuance path) can forge identity certificates that subsequently appear authentic to list_certificates and prove_certificate.

Affected

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

0.1.2 ≤ v < 0.3.40.3.1 ≤ v < 0.8.2
Affected range stops below 0.3.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 0.8.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (5)

x_refsource_CONFIRMExploitPatchVendor Advisory
Source: cverecord
https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j
x_refsource_MISCIssue Tracking
Source: cverecord
https://github.com/sgbett/bsv-ruby-sdk/issues/305
x_refsource_MISCIssue Tracking
Source: cverecord
https://github.com/sgbett/bsv-ruby-sdk/pull/306
x_refsource_MISCNot Applicable
Source: cverecord
https://brc.dev/52

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

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

CVSS

8.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-347

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