CVE-2026-123960
CriticalCVSS 9.9Summary
In TOTOLINK CA300-PoE version 6.2c.884, the setWanConfig function in /cgi-bin/cstecgi.cgi improperly handles the pppoeUser/priDns/secDns arguments, leading to a buffer overflow. The vulnerability can be exploited remotely, and a public exploit is already available.
Risk Assessment
A remote attacker could exploit the buffer overflow to destabilize the device or potentially achieve code execution, leading to compromise of the router and network.
Recommendation
Update the TOTOLINK CA300-PoE firmware to a non-vulnerable version as soon as possible, or restrict access to the management interface to trusted networks.
Other vulnerabilities in TOTOLINK CA300-PoE
See all- CVE-2026-123961Critical
A vulnerability was detected in TOTOLINK CA300-PoE version 6.2c.884 affecting the setWiFiBasicConfig function in /cgi-bin/cstecgi.cgi. Manipulation of the KeyStr argument leads to a buffer overflow. The attack can be initiated remotely and a public exploit is available.
- CVE-2026-123959Critical
In TOTOLINK CA300-PoE version 6.2c.884, the setLanguageCfg function in /cgi-bin/cstecgi.cgi improperly processes the langType argument, resulting in a buffer overflow. The attack can be initiated remotely, and the exploit has been publicly released.
- CVE-2026-123958Critical
In TOTOLINK CA300-PoE version 6.2c.884, the setLanConfig function in /cgi-bin/cstecgi.cgi mishandles the lanDns/lanSecDns/langType arguments, leading to a buffer overflow. The vulnerability can be exploited remotely, and a public exploit is already available.
- CVE-2026-123957Critical
In TOTOLINK CA300-PoE version 6.2c.884, the setIpQosRules function in /cgi-bin/cstecgi.cgi mishandles the ipStart argument, leading to a buffer overflow. The vulnerability can be exploited remotely, and the exploit has been publicly disclosed.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS