CVE-2026-26792

CriticalPublic PoCRCE

Published: 12 March 2026

Published

12 March 2026

Modified

16 March 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0111 78.4th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26792 is a critical-severity Command Injection (CWE-77) vulnerability in Gl-Inet Ar300M16 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 21.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

SI-10 requires information input validation at entry points like the set_upgrade parameters, directly preventing command injection vulnerabilities by sanitizing crafted inputs such as modem_url and firmware_upload.

SI-2 Flaw Remediation good match

prevent

SI-2 mandates identification, reporting, and timely remediation of flaws like these command injections in the GL-AR300M16 firmware, eliminating the vulnerability through patching.

AC-3 Access Enforcement good match

prevent

AC-3 enforces logical access controls on the vulnerable set_upgrade function, preventing unauthenticated remote attackers from supplying malicious parameters.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1059.004 Unix Shell Execution

Adversaries may abuse Unix shell commands and scripts for execution.

attack.mitre.org →

Why these techniques?

CVE enables remote exploitation of a public-facing router web interface (T1190) via command injection parameters, directly facilitating arbitrary Unix shell command execution (T1059.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

GL-iNet GL-AR300M16 v4.3.11 was discovered to contain multiple command injection vulnerabilities in the set_upgrade function via the modem_url, target_version, current_version, firmware_upload, hash_type, hash_value, and upgrade_type parameters. These vulnerabilities allow attackers to execute arbitrary commands via a crafted input.

Deeper analysisAI

CVE-2026-26792 involves multiple command injection vulnerabilities (CWE-77) in the GL-iNet GL-AR300M16 router running firmware version v4.3.11. The flaws exist in the set_upgrade function and can be triggered via crafted inputs to the parameters modem_url, target_version, current_version, firmware_upload, hash_type, hash_value, and upgrade_type. These issues allow attackers to execute arbitrary commands on the affected device.

The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating it is exploitable over the network with low complexity, no required privileges or user interaction, and high impacts on confidentiality, integrity, and availability. Remote attackers can leverage these command injections during firmware upgrade operations to run unauthorized commands, potentially leading to full device compromise.

Additional technical details, including a proof-of-concept, are documented in the GitHub repository at https://github.com/sezangel/IOT-vul/tree/main/GL-iNet/GL-AR300M16/set_upgrade. No vendor advisories or patches are referenced in the available information.