CVE-2026-86065

Description

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.

Overview

State: PUBLISHED
Assigner (CNA): GitHub_M
CVSS severity: HIGH
CVSS score: 7.5 / 10
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Effective score: 7.5 / 10 HIGH source: CNA overview
CWE(s): CWE-770
Reserved: 2026-09-04
Published: 2026-09-23 19:15 UTC
Last updated: 2026-09-23 19:15 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/86xxx/CVE-2026-86065.json
Linked Threat: CVE-2026-86065 — Klever-Go: Unauthenticated WebSocket /subscribe: no read-size limit, no connection cap, permissive origin -> remote node memory/goroutine exhaustion (DoS)

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-23 20:17:20 UTC
NVD last modified: 2026-09-23 20:17:20 UTC
NVD CVSS v3.1: 7.5 / 10 HIGH source: security-advisories@github.com
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-85575
Assigner: GitHub_M
Published: Sep 23, 2026, 7:15:24 PM
Updated: Sep 23, 2026, 7:15:24 PM
EUVD base score (CVSS 3.1): 7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EUVD-reported EPSS: 0.0000
Vendors: klever-io
Products: klever-go (< 1.7.20)
Aliases: GHSA-4fwh-wrm6-97xm

ENISA description: 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.

EUVD references (4)

Affected products (1)

Vendor	Product	Versions	Platforms
klever-io	klever-go	`< 1.7.20` (affected)	—

Vendor references (4)

References embedded in the original CVE record by the assigning CNA.

https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm x_refsource_CONFIRM
https://github.com/klever-io/klever-go/pull/76 x_refsource_MISC
https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2 x_refsource_MISC
https://github.com/klever-io/klever-go/releases/tag/v1.7.20 x_refsource_MISC

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (4)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2 security-advisories@github.com
https://github.com/klever-io/klever-go/pull/76 security-advisories@github.com
https://github.com/klever-io/klever-go/releases/tag/v1.7.20 security-advisories@github.com
https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm security-advisories@github.com

Remediations (10)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

Microsoft Defender Patch Bypass: High Severity Zero-Day Privilege ...

web:arcticwolf.com

Microsoft initially issued a patch (Engine v1.1.26060.3008) in July 2026 . However, on August 12, 2026 , a new exploit chain, "ShieldBreak," was released by the same researcher (alias "Chaotic Eclipse"), which publicly demonstrated a full bypass of Microsoft's patch and restored SYSTEM-level access.

2026-09-24 11:11 UTC
Microsoft Update Catalog

web:catalog.update.microsoft.com

Welcome to the Microsoft Update Catalog site. We want your feedback! Visit our newsgroup or send us an email to provide us with your thoughts and suggestions. To get started using the site, enter in your search terms in the Search box above or visit our FAQ for search tips. |Newsgroup|Send us your feedback

2026-09-24 11:11 UTC
Defender Zero-Day CVE-2026-50656 Under Active Exploit, No Patch

web:dailysecurityreview.com

Microsoft confirmed CVE - 2026 -50656, a zero-day in the Defender Malware Protection Engine allowing SYSTEM-level privilege escalation, is under active exploitation with no patch currently available.

2026-09-24 11:11 UTC
Security Update Guide - Microsoft Security Response Center

web:msrc.microsoft.com

Security Update Guide - Microsoft Security Response Center

2026-09-24 11:11 UTC
CVE-2026-0265 PAN-OS: Authentication Bypass with Cloud Authentication ...

web:security.paloaltonetworks.com

Palo Alto Networks Security Advisory: CVE - 2026 -0265 PAN-OS: Authentication Bypass with Cloud Authentication Service (CAS) enabled An authentication bypass vulnerability in Palo Alto Networks PAN-OS® software enables an unauthenticated attacker with network access to bypass authentication controls when Cloud Authentication Service (CAS) is enabled. The risk is higher if CAS is enabled on the ...

2026-09-24 11:11 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-24 11:11 UTC
Portal for ArcGIS Security 2026 Update 2 Patch - Esri Support

web:support.esri.com

This patch deals specifically with the issues listed below under Issues Addressed with this Patch . As part of the patch installation, the Portal for ArcGIS service is stopped and restarted. The restart may take several minutes depending on the number of items on the enterprise deployment. As a best practice, clear the browser cache and re-launch the browser after installing the patch . This ...

2026-09-24 11:11 UTC
August 2026 CVE Advisory Notification - Security

web:support.servicenow.com

Due to additional analysis provided by the security researcher who discovered CVE - 2026 -6876, we have upgraded the severity rating of CVE - 2026 -6876 from High to Critical. This change affects only the severity

2026-09-24 11:11 UTC
CVE-2026-50656 ShieldBreak Claims Defender Fix Bypass — Megathread

web:windowsforum.com

ShieldBreak, a newly published proof of concept from the researcher known as Nightmare Eclipse, claims to bypass Microsoft's July fix for the Microsoft Defender privilege-escalation flaw CVE - 2026 -50656, better known as RoguePlanet.

2026-09-24 11:11 UTC
What Is CVE Remediation in 2026? - aikido.dev

web:www.aikido.dev

CVE remediation is fixing known flaws in the software you run. Why upgrading often fails, what remediation actually involves, and how backporting fixes it.

2026-09-24 11:11 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-86065.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "klever-go",
          "vendor": "klever-io",
          "versions": [
            {
              "status": "affected",
              "version": "< 1.7.20"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-23T19:15:24.271Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/klever-io/klever-go/security/advisories/GHSA-4fwh-wrm6-97xm"
        },
        {
          "name": "https://github.com/klever-io/klever-go/pull/76",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/klever-io/klever-go/pull/76"
        },
        {
          "name": "https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/klever-io/klever-go/commit/b8af922e749ec1fa7451b2c6e7c9f634d8603be2"
        },
        {
          "name": "https://github.com/klever-io/klever-go/releases/tag/v1.7.20",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/klever-io/klever-go/releases/tag/v1.7.20"
        }
      ],
      "source": {
        "advisory": "GHSA-4fwh-wrm6-97xm",
        "discovery": "UNKNOWN"
      },
      "title": "Klever-Go: Unauthenticated WebSocket /subscribe: no read-size limit, no connection cap, permissive origin -> remote node memory/goroutine exhaustion (DoS)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-86065",
    "datePublished": "2026-09-23T19:15:24.271Z",
    "dateReserved": "2026-09-04T19:34:03.099Z",
    "dateUpdated": "2026-09-23T19:15:24.271Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}