Buffer Overflow Vulnerability in TOTOLINK CA300-PoE by TOTOLINK
CVE-2026-123961

9.4CRITICAL

Key Information:

Vendor

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

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-123961?

A security flaw has been identified in the TOTOLINK CA300-PoE, specifically affecting the setWiFiBasicConfig function located in the /cgi-bin/cstecgi.cgi file. This vulnerability arises from improper handling of the KeyStr argument, allowing for a buffer overflow condition. An attacker may exploit this weakness remotely, potentially leading to unauthorized access or control over the device. As the exploit has been publicly disclosed, it is critical for users of affected versions to assess their security measures and apply necessary patches.

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-2026-123961 - Proof of Concept

References

https://vuldb.com/vuln/432024
vdb-entrytechnical-description
https://vuldb.com/vuln/432024/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-123961
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)
.