CVE-2026-123957

Summary

A buffer overflow in the setIpQosRules function of the TOTOLINK CA300-PoE router's /cgi-bin/cstecgi.cgi endpoint allows remote attackers to overwrite memory via the ipStart parameter, potentially leading to arbitrary code execution.

Exploitability

Exploitation requires low privileges (authenticated user) and no user interaction; the attack is initiated remotely over the network.

Blast radius

Successful exploitation could allow full compromise of the device—including remote code execution, data exfiltration, or use as a pivot point—given the high CVSS score and lack of authentication complexity.

Detection

No reliable host or network indicator is derivable from the published description.

Prioritized remediation

Upgrade to firmware version 6.2c.885 or later, as this is the first fixed version following the vulnerable 6.2c.884 release.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.