---
id: CVE-2026-86065
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 default-open GET /subscribe endpoint in
  network/api/websocket/routes.go accepts unauthenticated WebSocket clients with
  permissive origin handling,…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: klever-io
product: github.com/klever-io/klever-go
affected:
  - github.com/klever-io/klever-go < 1.7.20
patched:
  - github.com/klever-io/klever-go 1.7.20
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:20.293'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86065'
references:
  - url: >-
      https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2
    label: security-advisories@github.com
  - url: 'https://github.com/klever-io/klever-go/pull/76'
    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-4fwh-wrm6-97xm
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-4fwh-wrm6-97xm'
  - url: 'https://github.com/klever-io/klever-go'
tags:
  - nvd
  - ghsa
  - go
  - cve.org
  - osv
aliases:
  - GHSA-4fwh-wrm6-97xm
ecosystem: go
ingestedAt: '2026-09-23T19:31:04.479Z'
epss: 0.0035
epssPercentile: 0.25901
---

## Overview

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the default-open GET /subscribe endpoint in network/api/websocket/routes.go accepts unauthenticated WebSocket clients with permissive origin handling, does not call SetReadLimit to bound message size, and has no live-connection cap. SocketHub.HandleClientInsertion also accepts an unbounded address list that grows addressSubscription, and client.loopIn continues reading without a size limit, allowing one client to grow subscription maps or many clients to retain goroutines, buffered channels, and descriptors. The global HTTP request throttler does not count upgraded live WebSocket connections. Because the REST and WebSocket API runs in the node process, memory or scheduler exhaustion can crash the node and interrupt P2P and consensus participation. 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-2026-86065)

Affected packages:

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

Patched in:

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

Source: https://github.com/advisories/GHSA-4fwh-wrm6-97xm