{"id":"CVE-2026-121600","published":"2026-11-04T01:17:23.647","lastModified":"2026-11-04T01:17:23.823","description":"A flaw has been found in TOTOLINK A950RG 4.1.2cu.5268_B20221104. Affected by this vulnerability is the function setMacFilterRules of the file /cgi-bin/cstecgi.cgi of the component MAC Filter Handler. This manipulation of the argument addEffect causes stack-based buffer overflow. The attack can be initiated remotely. The exploit has been published and may be used.","cvssScore":9.9,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cwes":["CWE-119","CWE-121"],"vendors":[],"products":[],"references":[{"url":"https://gist.github.com/H3rmesk1t/217c00b12e04fcde07c453a55579f808","tags":[]},{"url":"https://vuldb.com/cve/CVE-2026-121600","tags":[]},{"url":"https://vuldb.com/submit/1022562","tags":[]},{"url":"https://vuldb.com/vuln/430442","tags":[]},{"url":"https://vuldb.com/vuln/430442/cti","tags":[]},{"url":"https://www.totolink.net/","tags":[]}],"exploitRefs":[{"url":"https://gist.github.com/H3rmesk1t/217c00b12e04fcde07c453a55579f808","tags":[]}],"hasPoc":true,"ai":{"summary":"A stack-based buffer overflow in the MAC Filter Handler of TOTOLINK A950RG firmware v4.1.2cu.5268_B20221104 allows remote attackers to overwrite memory via the addEffect parameter in the setMacFilterRules function, leading to potential code execution or device crash.","exploitability":"Exploitation requires low privileges (authenticated user) and no user interaction; the exploit is publicly available.","blast_radius":"Successful exploitation could allow full compromise of the device—including remote code execution, data exfiltration, or denial of service—with potential lateral movement to other devices on the same network.","remediation":"Upgrade to firmware version 4.1.2cu.5268_B20221104_P1 or later if available; if no patched version is published, disable MAC filtering functionality and restrict access to /cgi-bin/cstecgi.cgi via network segmentation.","detection":"Look for HTTP POST requests to /cgi-bin/cstecgi.cgi with abnormally long addEffect parameter values (e.g., >256 bytes) in web server or application logs; unauthenticated or unexpected access attempts to this endpoint may also be observable.","tags":["buffer-overflow","rce","web","iot","authenticated"],"model":"garnet-coder","analyzedAt":"2026-11-04T09:44:12.636Z"}}