Summary
CVE-2026-18602 is an unauthenticated OS command injection vulnerability (CWE-77) in the GL.iNet GL-MT3000 router. An attacker can reach the device’s RPC interface over the network and execute arbitrary commands as root without authentication or user interaction, making this a critical-severity remote code execution flaw.
Technical details
- Root cause: The
ovpn-clientnative plugin (ovpn-client.so, loaded via/usr/lib/oui-httpd/rpc/) embeds the attacker-suppliedhostnamevalue directly into a shell command viasprintf()without sanitization or escaping. - Trigger conditions: A crafted RPC request to the
/cgi-bin/glcendpoint invoking theovpn-clientobject’sget_recommend_configmethod, supplying ahostnamevalue containing shell command-substitution syntax (e.g.$(...)). - Attack vector: Network (NETWORK). The
/cgi-bin/glcRPC handler processes the request without any authentication check. - Impact: Injected commands execute with root privileges, resulting in full remote code execution and complete compromise of the device.
Affected software
- GL.iNet GL-MT3000 firmware versions 4.4.0, 4.4.1, 4.4.2, 4.4.3, 4.4.4, and 4.4.5.
Severity
- CVSS v3.1 base score: 9.8 (Critical) — vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. - The CNA also assigned a CVSS v4.0 base score of 9.3 (Critical) — vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N.
Mitigation and recommended actions
- Immediate: No fixed firmware version is identified in the CVE record. Monitor the GL.iNet security-updates page and upgrade GL-MT3000 devices to the latest available firmware as soon as a fix is published.
- If no patch: Do not expose the router’s web/administration interface to the internet. Restrict access to the management interface (and the
/cgi-bin/glcendpoint) to trusted internal networks via firewall rules or ACLs, and disable remote/WAN-side administration.
How IONIX identifies potentially affected assets
IONIX matches the following signals against data already collected when it crawled the asset; identifying the technology sends no request beyond that crawl.
- Page title:
GL.iNet,GL-MT3000,Beryl AX,GL.iNet Admin Panel

