CVE-2026-123958
CriticalCVSS 9.9Summary
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.
Risk Assessment
A remote attacker could trigger a buffer overflow and potentially take control of the device or cause a denial of service. Since the exploit is public, the risk of exploitation is high.
Recommendation
Update TOTOLINK CA300-PoE firmware to the latest version or restrict access to the management interface. Until a patch is available, consider isolating the device on the network.
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-2026-123960Critical
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.
- 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-2026-123957Critical
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 vulnerability was identified in TOTOLINK CA300-PoE 6.2c.884. The affected element is the function setLanConfig of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument lanDns/lanSecDns/langType leads to buffer overflow. It is possible to launch the attack remotely. The exploit is publicly available and might be used.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS