CVE-2026-40070
bsv-sdk and bsv-wallet persist unverified certifier signatures in acquire_certificate (direct and issuance paths)
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.
INFO
Published Date :
April 9, 2026, 6:17 p.m.
Last Modified :
April 24, 2026, 5:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-40070
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update BSV Ruby SDK to version 0.8.2 or later.
- Ensure all certificate signatures are verified.
- Validate data received from certifier endpoints.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40070.
| URL | Resource |
|---|---|
| https://brc.dev/52 | Not Applicable |
| https://github.com/sgbett/bsv-ruby-sdk/commit/4992e8a265fd914a7eeb0405c69d1ff0122a84cc | Release Notes |
| https://github.com/sgbett/bsv-ruby-sdk/issues/305 | Issue Tracking |
| https://github.com/sgbett/bsv-ruby-sdk/pull/306 | Issue Tracking |
| https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j | Exploit Patch Vendor Advisory |
| https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40070 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40070
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40070 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40070 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 24, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:sgbett:bsv-wallet:*:*:*:*:*:ruby:*:* versions from (including) 0.1.2 up to (excluding) 0.3.4 *cpe:2.3:a:sgbett:bsv_ruby_sdk:*:*:*:*:*:ruby:*:* versions from (including) 0.3.1 up to (excluding) 0.8.2 Added Reference Type GitHub, Inc.: https://brc.dev/52 Types: Not Applicable Added Reference Type GitHub, Inc.: https://github.com/sgbett/bsv-ruby-sdk/commit/4992e8a265fd914a7eeb0405c69d1ff0122a84cc Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/sgbett/bsv-ruby-sdk/issues/305 Types: Issue Tracking Added Reference Type GitHub, Inc.: https://github.com/sgbett/bsv-ruby-sdk/pull/306 Types: Issue Tracking Added Reference Type CISA-ADP: https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j Types: Exploit, Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 13, 2026
Action Type Old Value New Value Added Reference https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j -
New CVE Received by [email protected]
Apr. 09, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-347 Added Reference https://brc.dev/52 Added Reference https://github.com/sgbett/bsv-ruby-sdk/commit/4992e8a265fd914a7eeb0405c69d1ff0122a84cc Added Reference https://github.com/sgbett/bsv-ruby-sdk/issues/305 Added Reference https://github.com/sgbett/bsv-ruby-sdk/pull/306 Added Reference https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j