CVE-2026-36540 — HIGH (7.3)

Vulnerability Description

Netis AC1200 Router NC21 V4.0.1.4296 is vulnerable to unauthenticated command injection via the /cgi-bin/skk_set.cgi endpoint. The password and new_pwd_confirm POST parameters are passed directly to the underlying OS shell without sanitization. An attacker can inject arbitrary shell commands by wrapping them in backticks (`) and encoding them in base64. Because the endpoint requires no authentication, any device on the LAN can achieve full Remote Code Execution on the router's operating system with a single HTTP POST request.

CVSS Score

7.3

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

LOW

Availability

LOW

Related Weaknesses (CWE)

CWE-77

References

FAQ

What is CVE-2026-36540?

CVE-2026-36540 is a vulnerability with a CVSS score of 7.3 (HIGH). Netis AC1200 Router NC21 V4.0.1.4296 is vulnerable to unauthenticated command injection via the /cgi-bin/skk_set.cgi endpoint. The password and new_pwd_confirm POST parameters are passed directly to t...

How severe is CVE-2026-36540?

CVE-2026-36540 has been rated HIGH with a CVSS base score of 7.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-36540?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.