CVE-2026-40070bsv-sdk and bsv-wallet persist unverified certifier signatures in acquire_certificate (direct and issuance paths)
- 8.1HighCVSS base score
- 0.14%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Analyzed | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.14% · top 97% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected >= 0.3.1, < 0.8.2
- affected >= 0.3.1, < 0.8.2
- affected >= 0.1.2, < 0.3.4
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsbsv-sdkGHSA-hc36-c89j-5f4j (opens in a new tab)
- RubyGemsbsv-walletGHSA-hc36-c89j-5f4j (opens in a new tab)
References
References5
- https://github.com/sgbett/bsv-ruby-sdk/security/advisories/GHSA-hc36-c89j-5f4j (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/sgbett/bsv-ruby-sdk/issues/305 (opens in a new tab)x_refsource_MISC
- https://github.com/sgbett/bsv-ruby-sdk/pull/306 (opens in a new tab)x_refsource_MISC
- https://github.com/sgbett/bsv-ruby-sdk/commit/4992e8a265fd914a7eeb0405c69d1ff0122a84cc (opens in a new tab)x_refsource_MISC
- https://brc.dev/52 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-20996 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-hc36-c89j-5f4j (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-40070)Record last updated .