CVE-2026-82407

Description

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.

Overview

State: PUBLISHED
Assigner (CNA): GitHub_M
CVSS severity: HIGH
CVSS score: 7.0 / 10
CVSS vector: 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
Effective score: 7.0 / 10 HIGH source: CNA overview
CWE(s): CWE-20
Reserved: 2026-08-28
Published: 2026-09-23 19:17 UTC
Last updated: 2026-09-23 19:42 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/82xxx/CVE-2026-82407.json
Linked Threat: CVE-2026-82407 — Klever-Go: Validator registration accepts an unvalidated BLS public key → consensus liveness 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 20:17:16 UTC
NVD last modified: 2026-09-23 20:17:16 UTC

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-2026-85576

EUVD enrichment is queued; refresh the page in a few seconds.

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-9wh6-9hq7-9688 x_refsource_CONFIRM
https://github.com/klever-io/klever-go/commit/11606a90ccc289f93d0175994733229b332d9cff x_refsource_MISC
https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f 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 (5)

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/11606a90ccc289f93d0175994733229b332d9cff security-advisories@github.com
https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f 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-9wh6-9hq7-9688 security-advisories@github.com
https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688 134c704f-9b21-4f2e-91b3-4a467353bcc0

Remediations (10)

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

Microsoft Exchange CVE-2026-42897 Patch and OWA Mitigation Guide

web:fixitphill.com

Patch Microsoft Exchange CVE - 2026 -42897 with June 2026 security updates, keep EEMS mitigations during rollout, and verify OWA and mail flow.

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

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

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
CVE-2026-42897 Exchange OWA Mitigation M2: Admin Checks

web:windowsforum.com

Microsoft's Fastest Fix Is a Mitigation , Not a Patch The important detail in Microsoft's May 14 notice is that there is no permanent Exchange security update available yet for CVE - 2026 -42897. Microsoft says it is working on one and will release it later for affected supported paths, but today's defensive action is mitigation .

2026-09-24 11:11 UTC
Microsoft August 2026 Patch Tuesday fixes 400 flaws, 3 zero-days

web:www.bleepingcomputer.com

Today is Microsoft's August 2026 Patch Tuesday, and with it comes security updates for a massive 400 flaws, including one actively exploited and two publicly disclosed zero-day vulnerabilities.

2026-09-24 11:11 UTC
Critical Patches Issued for Microsoft Products, August 11, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-09-24 11:11 UTC
August's Patch Tuesday is a monster: 751 fixes, with an exploited ...

web:www.computerworld.com

August's Patch Tuesday is a big one: 751 fixes, an exploited WinSock flaw and plenty of critical Windows, Office and Exchange issues.

2026-09-24 11:11 UTC
Microsoft Confirms Active 0-Day Exploit—Check Emergency Mitigation

web:www.forbes.com

Updated May 18: This article has been updated to include further details on the emergency mitigation process recommended by Microsoft after the CVE - 2026 -42897 Exchange Server zero-day was ...

2026-09-24 11:11 UTC
Patch Tuesday: Update now to fix 421 flaws, including three zero ...

web:www.malwarebytes.com

Microsoft's August 2026 Patch Tuesday addresses 421 Microsoft vulnerabilities, including 62 rated Critical. One Windows vulnerability has been exploited in the wild by the Lazarus group to gain SYSTEM privileges. The August update is smaller than July's record-breaking release, but it's still ...

2026-09-24 11:11 UTC
CVE-2026-82407: klever-io klever-go: Klever-Go is the Go ... - Rapid7

web:www.rapid7.com

CVE-2026-82407 : klever-io klever-go: Klever-Go is the Go implementation of the Klever blockchain protocol. View severity, references, and remediation details from Rapid7.

2026-09-24 11:11 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-82407.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-82407",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-23T19:41:57.322149Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-23T19:42:17.556Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "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, 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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-23T19:17:59.006Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688"
        },
        {
          "name": "https://github.com/klever-io/klever-go/commit/11606a90ccc289f93d0175994733229b332d9cff",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/klever-io/klever-go/commit/11606a90ccc289f93d0175994733229b332d9cff"
        },
        {
          "name": "https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f"
        },
        {
          "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-9wh6-9hq7-9688",
        "discovery": "UNKNOWN"
      },
      "title": "Klever-Go: Validator registration accepts an unvalidated BLS public key \u2192 consensus liveness DoS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-82407",
    "datePublished": "2026-09-23T19:17:59.006Z",
    "dateReserved": "2026-08-28T22:00:43.513Z",
    "dateUpdated": "2026-09-23T19:42:17.556Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}