CVE-2026-123959

Description

A security flaw has been discovered in TOTOLINK CA300-PoE 6.2c.884. The impacted element is the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument langType results in buffer overflow. The attack can be initiated remotely. The exploit has been released to the public and may be used for attacks.

Overview

State: PUBLISHED
Assigner (CNA): VulDB
CVSS severity: CRITICAL
CVSS score: 9.4 / 10
CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
Effective score: 9.4 / 10 CRITICAL source: CNA overview
CWE(s): CWE-120, CWE-119
Reserved: 2026-11-06
Published: 2026-11-07 09:45 UTC
Last updated: 2026-11-07 09:45 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/123xxx/CVE-2026-123959.json
Linked Threat: CVE-2026-123959 — TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow

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-2026-119111

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

Affected products (1)

Vendor	Product	Versions	Platforms
TOTOLINK	CA300-PoE	`6.2c.884` (affected)	—

Vendor references (6)

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

VDB-432022 | TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow vdb-entrytechnical-description
VDB-432022 | CTI Indicators (IOB, IOC, IOA) signaturepermissions-required
CVE-2026-123959 | CVE Analysis and Report third-party-advisory
Submit #1033721 | TOTOLINK CA300-PoE CA300-PoE_Firmware V6.2c.884 Buffer Overflow third-party-advisory
https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanguageCfg-3f953a41781f80199f44f227136a1441?source=copy_link exploit
https://www.totolink.net/ broken-linkproduct

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.

Remediations (10)

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

CVEs and Security Vulnerabilities - OpenCVE

web:app.opencve.io

Explore the latest vulnerabilities and security issues in the CVE database

2026-11-08 10:21 UTC
CVE Vulnerabilities 2026: Critical Flaws & Fixes Hub

web:cyberupdates365.com

Track critical CVE vulnerabilities 2026 with verified enterprise patch guides. Fix zero-days across VMware, WordPress, Windows, and cloud infrastructure.

2026-11-08 10:21 UTC
Security Advisories and Bulletins | Microsoft Learn

web:learn.microsoft.com

In this library you will find the following security documents that have been released by the Microsoft Security Response Center (MSRC). The MSRC investigates all reports of security vulnerabilities affecting Microsoft products and services, and releases these documents as part of the ongoing effort ...

2026-11-08 10:21 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.

2026-11-08 10:21 UTC
Microsoft Patch Tracker (November 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.

2026-11-08 10:21 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.

2026-11-08 10:21 UTC
Microsoft October 2026 Patch Tuesday fixes 1,411 flaws, 3 zero-days

web:www.bleepingcomputer.com

Today is Microsoft's October 2026 Patch Tuesday, with security updates addressing a record-breaking 1,411 flaws, including one actively exploited and two publicly disclosed zero-day vulnerabilities.

2026-11-08 10:21 UTC
Patch now: PHP2Shell, Brotli, and eMudhra guidance for customers

web:www.microsoft.com

If you can't patch immediately: Apply the PHP project's interim mitigations and the Azure WAF protections. Note: This reduces exposure but doesn't fix the underlying vulnerabilities.

2026-11-08 10:21 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-11-08 10:21 UTC
Oracle Critical Security Patch Update Advisory - September 2026

web:www.oracle.com

Prior Critical Patch Update and Critical Security Patch Update advisories should be reviewed for information regarding earlier published security patches. Refer to Critical Patch Updates, Critical Security Patch Updates, Security Alerts and Bulletins for information about Oracle Security advisories.

2026-11-08 10:21 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-123959.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "cpes": [
            "cpe:2.3:o:totolink:ca300-poe_firmware:*:*:*:*:*:*:*:*"
          ],
          "product": "CA300-PoE",
          "vendor": "TOTOLINK",
          "versions": [
            {
              "status": "affected",
              "version": "6.2c.884"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "wxhwxhwxh_mie (VulDB User)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A security flaw has been discovered in TOTOLINK CA300-PoE 6.2c.884. The impacted element is the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument langType results in buffer overflow. The attack can be initiated remotely. The exploit has been released to the public and may be used for attacks."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "baseScore": 9.4,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P",
            "version": "4.0"
          }
        },
        {
          "cvssV3_1": {
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C",
            "version": "3.1"
          }
        },
        {
          "cvssV3_0": {
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            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C",
            "version": "3.0"
          }
        },
        {
          "cvssV2_0": {
            "baseScore": 8.3,
            "vectorString": "AV:N/AC:L/Au:M/C:C/I:C/A:C/E:POC/RL:ND/RC:C",
            "version": "2.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-120",
              "description": "Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-119",
              "description": "Memory Corruption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-07T09:45:26.355Z",
        "orgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
        "shortName": "VulDB"
      },
      "references": [
        {
          "name": "VDB-432022 | TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow",
          "tags": [
            "vdb-entry",
            "technical-description"
          ],
          "url": "https://vuldb.com/vuln/432022"
        },
        {
          "name": "VDB-432022 | CTI Indicators (IOB, IOC, IOA)",
          "tags": [
            "signature",
            "permissions-required"
          ],
          "url": "https://vuldb.com/vuln/432022/cti"
        },
        {
          "name": "CVE-2026-123959 | CVE Analysis and Report",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://vuldb.com/cve/CVE-2026-123959"
        },
        {
          "name": "Submit #1033721 | TOTOLINK CA300-PoE CA300-PoE_Firmware V6.2c.884 Buffer Overflow",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://vuldb.com/submit/1033721"
        },
        {
          "tags": [
            "exploit"
          ],
          "url": "https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanguageCfg-3f953a41781f80199f44f227136a1441?source=copy_link"
        },
        {
          "tags": [
            "broken-link",
            "product"
          ],
          "url": "https://www.totolink.net/"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-11-06T00:00:00.000Z",
          "value": "Advisory disclosed"
        },
        {
          "lang": "en",
          "time": "2026-11-06T01:00:00.000Z",
          "value": "VulDB entry created"
        },
        {
          "lang": "en",
          "time": "2026-11-06T18:12:40.000Z",
          "value": "VulDB entry last update"
        }
      ],
      "title": "TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow",
      "x_generator": [
        "VulDB PVTS v202611"
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
    "assignerShortName": "VulDB",
    "cveId": "CVE-2026-123959",
    "datePublished": "2026-11-07T09:45:26.355Z",
    "dateReserved": "2026-11-06T17:07:18.910Z",
    "dateUpdated": "2026-11-07T09:45:26.355Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}