Buffer Overflow Vulnerability in TOTOLINK CA300-PoE Device
CVE-2026-123960

9.4CRITICAL

Key Information:

Vendor

Totolink
Status
Ca300-poe
Vendor
CVE Published:
7 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-123960?

A vulnerability has been discovered in the TOTOLINK CA300-PoE device version 6.2c.884 related to the setWanConfig function in the cgi-bin/cstecgi.cgi file. This weakness arises from improper handling of the pppoeUser, priDns, and secDns arguments, potentially leading to a buffer overflow. The flaw could be exploited remotely, enabling attackers to manipulate the device's configuration without prior authentication. Publicly available exploit code raises further concerns about the security of affected systems.

Affected Version(s)

CA300-PoE 6.2c.884

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-123960 - Proof of Concept

References

https://vuldb.com/vuln/432023
vdb-entrytechnical-description
https://vuldb.com/vuln/432023/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-123960
third-party-advisory

CVSS V4

Score:
9.4
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

wxhwxhwxh_mie (VulDB User)
.