---
id: CVE-2026-82406
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, the native marketplace function core/kapp/market/market.go Buy does
  not check IsClaimed before accepting a bid. A seller can use the Claim
  seller-acce…
severity: high
cvss: 7.1
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-841
vendor: klever-io
product: klever-go
affected:
  - klever-go < 1.7.20
patched:
  - github.com/klever-io/klever-go 1.7.20
published: '2026-09-23'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:12.287'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82406'
references:
  - url: >-
      https://github.com/klever-io/klever-go/commit/063bb3ed98f9a84a4b1f7286680613a5fc3c91b2
    label: security-advisories@github.com
  - url: 'https://github.com/klever-io/klever-go/pull/16'
    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-26r5-4mm2-px5c
    label: security-advisories@github.com
  - url: >-
      https://github.com/klever-io/klever-go/security/advisories/GHSA-26r5-4mm2-px5c
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-26r5-4mm2-px5c'
  - url: 'https://github.com/klever-io/klever-go'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
  - osv
  - exploit-available
aliases:
  - GHSA-26r5-4mm2-px5c
ecosystem: go
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-24T15:20:43.702470Z'
cvssSource: cna
ingestedAt: '2026-09-23T19:31:04.482Z'
epss: 0.00341
epssPercentile: 0.24871
---

## Overview

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the native marketplace function core/kapp/market/market.go Buy does not check IsClaimed before accepting a bid. A seller can use the Claim seller-accept branch to settle a resting-bid auction while leaving the claimed order loadable with a future EndTime and stale CurrentBid and CurrentBidder values. A later bidder can submit a higher bid, be debited, and cause the previous bidder to receive a refund even though the NFT has already been delivered. Because Claim and CancelOrder reject the later bidder when IsClaimed is true, the later bidder cannot obtain the NFT or recover the funds. 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-2026-82406)

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-26r5-4mm2-px5c