---
id: CVE-2026-82407
title: Klever-Go is the Go implementation of the Klever blockchain protocol
summary: >-
  Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to
  1.7.20, core/kapp/validators/validators.go Register and the runtime validator
  update path accept a submitted BLSPublicKey without curve, prime-order
  subgroup,…
severity: high
cvss: 7
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H'
cwe:
  - CWE-20
vendor: klever-io
product: klever-go
affected:
  - klever-go < 1.7.20
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:16.847'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82407'
references:
  - url: >-
      https://github.com/klever-io/klever-go/commit/11606a90ccc289f93d0175994733229b332d9cff
    label: security-advisories@github.com
  - url: >-
      https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f
    label: security-advisories@github.com
  - url: 'https://github.com/klever-io/klever-go/releases/tag/v1.7.20'
    label: security-advisories@github.com
  - url: >-
      https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688
    label: security-advisories@github.com
  - url: >-
      https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-9wh6-9hq7-9688'
  - url: 'https://github.com/klever-io/klever-go'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - go
  - osv
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T19:41:57.322149Z'
cvssSource: cna
ingestedAt: '2026-09-23T19:31:04.481Z'
aliases:
  - GHSA-9wh6-9hq7-9688
ecosystem: go
patched:
  - github.com/klever-io/klever-go 1.7.20
epss: 0.00434
epssPercentile: 0.34943
---

## Overview

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, core/kapp/validators/validators.go Register and the runtime validator update path accept a submitted BLSPublicKey without curve, prime-order subgroup, or nonzero validation. When a validator with a malformed key becomes eligible and is selected into a consensus group, MultiSigner.Reset and the corresponding signature verification creation path cannot deserialize the group key and cancel the slot. This causes repeated missed rounds and throughput degradation, and a network whose consensus group equals the eligible validator set can halt completely. Genesis validation is not affected because that path already performs CheckPublicKeyValid. This issue is fixed in version 1.7.20.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-82407)

Affected packages:

- `github.com/klever-io/klever-go <= 1.7.19`

Patched in:

- `github.com/klever-io/klever-go 1.7.20`

Source: https://github.com/advisories/GHSA-9wh6-9hq7-9688