---
id: "CVE-2026-123960"
page: "https://infrastack.ai/live/CVE-2026-123960"
kind: "vulnerability"
aliases: ["CVE-2026-123960"]
title: "TOTOLINK CA300-PoE router: WAN setup flaw allows remote buffer overflow"
severity: "critical"
cvss: 9.9
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "CA300-PoE firmware", "fixed": [], "affected": "6.2c.884", "ecosystem": "vendor"}]
ecosystems: []
tags: ["ca300-poe", "infrastructure", "iot", "routers", "totolink"]
not_affected_if: ["admin-interface-not-exposed", "other-firmware"]
published_at: "2026-11-07T10:17:12+00:00"
first_seen_at: "2026-11-07T10:46:41+00:00"
updated_at: "2026-11-07T10:49:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123960", "first_seen_at": "2026-11-07T10:46:41+00:00"}, {"source": "analyst", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123960", "first_seen_at": "2026-11-07T10:49:30+00:00", "cites": ["https://nvd.nist.gov/vuln/detail/CVE-2026-123960"]}]
exploit_sources: []
---

# TOTOLINK CA300-PoE router: WAN setup flaw allows remote buffer overflow

Link for people: https://infrastack.ai/live/CVE-2026-123960 (this .md is for agents)

The TOTOLINK CA300-PoE 6.2c.884 web interface has a buffer overflow in its setWanConfig handler at /cgi-bin/cstecgi.cgi, triggered through the pppoeUser, priDns and secDns arguments. A remote attacker can send crafted requests to overflow memory, and a public exploit has been released.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:CA300-PoE firmware affected 6.2c.884 fixed no fixed version listed

## How to check

- Check the firmware version on the device admin page; the affected version is `6.2c.884`.
- Confirm whether the web management interface is reachable from the internet or untrusted networks.
- Look for requests to `/cgi-bin/cstecgi.cgi` with `setWanConfig` in access logs.

## Timeline

- 2026-11-07T10:46:41+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123960
- 2026-11-07T10:49:30+00:00 analyst https://nvd.nist.gov/vuln/detail/CVE-2026-123960 — Only NVD/VulDB-sourced record found (CNA vuldb). No TOTOLINK advisory or fixed firmware located; no vendor page saying no fix, so fix left unknown. CVSS 4.0 vector has PR:L, so some login likely needed, not confirmed by vendor. Public exploit claimed by CNA, no link found. Sibling CA300-PoE CVEs 123957-59 same pattern. Nothing verified.

## Documents

- [describes] NVD CVE-2026-123960 https://nvd.nist.gov/vuln/detail/CVE-2026-123960

## From the sources

A weakness has been identified in TOTOLINK CA300-PoE 6.2c.884. This affects the function setWanConfig of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument pppoeUser/priDns/secDns can lead to buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks.

---

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