CVE-2026-123960

TOTOLINK CA300-PoE cstecgi.cgi setWanConfig buffer overflow

9.4 Critical

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.80%Scored on 2026-11-07. The trend appears after a second daily score.

What each source reports

CVE List Score used 9.4

TOTOLINK CA300-PoE cstecgi.cgi setWanConfig buffer overflow

Record: CVE-2026-123960
CVSS 4.0: 9.4 CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
CVSS 3.1: 9.9 CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C
CVSS 3.0: 9.9 CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C
CVSS 2.0: 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C
Weakness: CWE-120, CWE-119
Updated: 2026-11-07

EUVDEUVD-2026-119110 9.4

Record: EUVD-2026-119110
CVSS 4.0: 9.4 CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
Updated: 2026-11-07

GitHub AdvisoriesGHSA-gmwv-c623-rw5f 8.6

A weakness has been identified in TOTOLINK CA300-PoE 6.2c.884. This affects the function...

Record: GHSA-gmwv-c623-rw5f
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 9.9 CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-119
Updated: 2026-11-07

NVD 8.6

Record: CVE-2026-123960
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 9.9 CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 2.0: 9.0 HighAV:N/AC:L/Au:S/C:C/I:C/A:C
Weakness: CWE-119, CWE-120
Updated: 2026-11-07

Affected products

totolink ca300-poe

History

History
Recorded	Changed	Sources
Nov 7, 2026	published	EUVD
Nov 7, 2026	published	EUVD
Nov 7, 2026	aliases, references	GitHub Advisories, NVD
Nov 7, 2026	cwes, references, severity, title	CVE List
Nov 7, 2026	first indexed	EUVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-123960 is a critical vulnerability (CVSS 9.4) in Totolink Ca300-poe, published November 7, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.80%, the 56th percentile. No source names a fixed version.