Buffer Overflow Vulnerability in TOTOLINK CA300-PoE Router
CVE-2026-123958

9.4CRITICAL

Key Information:

Vendor

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

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-123958?

A vulnerability exists in the TOTOLINK CA300-PoE 6.2c.884 router that affects the setLanConfig function within the /cgi-bin/cstecgi.cgi file. By manipulating the parameters lanDns, lanSecDns, and langType, an attacker can trigger a buffer overflow. This can potentially allow for remote exploitation, with publicly available exploits that could be leveraged by malicious actors. It is crucial for users to assess their systems and apply necessary security measures to mitigate this risk.

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-2026-123958 - Proof of Concept

References

https://vuldb.com/vuln/432021
vdb-entrytechnical-description
https://vuldb.com/vuln/432021/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-123958
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)
.