Atomicorp WAF Research Note: CVE-2026-71926

DrayTek VigorSwitch Multiple Models OS Command Injection via setDevice

CVE Details

• Already protected by existing Atomicorp WAF rules
• Protection status: Understanding Atomicorp WAF Protection Status
• CVE: CVE-2026-71926
• Name: DrayTek VigorSwitch Multiple Models OS Command Injection via setDevice
• Severity: High
• CVSS: 8.6 (v4.0) (High)
• CVSS version: 4.0
• CVSS source: VulnCheck CNA
• CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
  • Attack vector: Network
  • Attack complexity: Low
  • Attack requirements: None
  • Privileges required: High
  • User interaction: None
  • Vulnerable-system confidentiality: High
  • Vulnerable-system integrity: High
  • Vulnerable-system availability: High
  • Subsequent-system confidentiality: None
  • Subsequent-system integrity: None
  • Subsequent-system availability: None
  • Scope: X
• CWE: CWE-78 — Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)
• Related CAPEC attack patterns (via MITRE CWE relationships): CAPEC-108 (opens in a new tab) , CAPEC-15 (opens in a new tab) , CAPEC-43 (opens in a new tab) , CAPEC-6 (opens in a new tab) , CAPEC-88 (opens in a new tab)
• Vendor: DrayTek Corporation
• Vulnerable products: VigorSwitch G2540xs , VigorSwitch P2540xs , VigorSwitch FX2120 , VigorSwitch G2282x , VigorSwitch P2282x , VigorSwitch Q2300x , VigorSwitch PQ2300xb , VigorSwitch G2542x , VigorSwitch P2542x , VigorSwitch P2542xh , VigorSwitch PX2060 , VigorSwitch G1280 , VigorSwitch P1280 , VigorSwitch P1281x , VigorSwitch G1282 , VigorSwitch P1282 , VigorSwitch G2121 , VigorSwitch P2121 , VigorSwitch PQ2121x , VigorSwitch Q2121x , VigorSwitch G2280x , VigorSwitch P2280x , VigorSwitch Q2200x , VigorSwitch PQ2200xb , VigorSwitch G2100 , VigorSwitch P2100 , VigorSwitch G2540x , VigorSwitch P2540x
• CVE published: 2026-08-24
• CVE last modified: 2026-08-27
• EPSS: 0.0167; 75.4th percentile (FIRST (opens in a new tab) )
• Latest Update: 2026-09-06
• Selected Rule IDs observed: 340014 , 340023 , 340029 , 344360 , 344361 , 344363 , 344364 , 344366 , 344370 , 393655
• Matching rules: 10; rules with blocking actions: 10
• Would-block Rule IDs: 340014 , 340023 , 340029 , 344360 , 344361 , 344363 , 344364 , 344366 , 344370 , 393655
• Request surfaces inspected: JSON request data, Request URI, Request argument names, Request arguments, Request cookies, SOAP request data, XML request data

Vulnerability Description

Multiple DrayTek VigorSwitch models contain a command injection vulnerability in the setDevice function. The vulnerability is caused by insufficient sanitization of the username, password, and location fields before command execution. A remote attacker can trigger this vulnerability via crafted input to execute arbitrary commands with root privileges. Exploitation requires valid administrative credentials for the device’s web management interface.

Recommended Actions

1. Maintain the observed Atomicorp protections. Keep your Atomicorp commercial rules current and confirm that the selected observed rules (340014 , 340023 , 340029 , 344360 , 344361 , 344363 , 344364 , 344366 , 344370 , 393655 ) have not been locally disabled. Atomicorp commercial rules are enabled by default. If you use Atomic WAF, review the applicable policy and rule settings.

2. Apply the vendor’s remediation. WAF protection is defense in depth and does not replace upgrading or following the affected vendor’s guidance.

   • Affected versions: DrayTek Corporation VigorSwitch G2540xs versions earlier than 3.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P2540xs versions earlier than 3.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch FX2120 versions earlier than 3.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G2282x versions earlier than 2.10.6.
   • Affected versions: DrayTek Corporation VigorSwitch P2282x versions earlier than 2.10.6.
   • Affected versions: DrayTek Corporation VigorSwitch Q2300x versions earlier than 2.10.7.
   • Affected versions: DrayTek Corporation VigorSwitch PQ2300xb versions earlier than 2.10.7.
   • Affected versions: DrayTek Corporation VigorSwitch G2542x versions earlier than 3.10.6.
   • Affected versions: DrayTek Corporation VigorSwitch P2542x versions earlier than 3.10.6.
   • Affected versions: DrayTek Corporation VigorSwitch P2542xh versions earlier than 3.10.6.
   • Affected versions: DrayTek Corporation VigorSwitch PX2060 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G1280 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P1280 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P1281x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G1282 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P1282 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G2121 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P2121 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch PQ2121x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch Q2121x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G2280x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P2280x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch Q2200x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch PQ2200xb versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G2100 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P2100 versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch G2540x versions earlier than 2.9.10.
   • Affected versions: DrayTek Corporation VigorSwitch P2540x versions earlier than 2.9.10.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2540xs to 3.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2540xs to 3.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch FX2120 to 3.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2282x to 2.10.6 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2282x to 2.10.6 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch Q2300x to 2.10.7 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch PQ2300xb to 2.10.7 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2542x to 3.10.6 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2542x to 3.10.6 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2542xh to 3.10.6 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch PX2060 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G1280 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P1280 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P1281x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G1282 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P1282 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2121 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2121 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch PQ2121x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch Q2121x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2280x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2280x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch Q2200x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch PQ2200xb to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2100 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2100 to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch G2540x to 2.9.10 or later.
   • Recommended upgrade: Upgrade DrayTek Corporation VigorSwitch P2540x to 2.9.10 or later.

3. Validate after changes. Confirm rule updates are current, review WAF events for the affected application, and test application behavior after vendor upgrades, mitigations, or local policy changes.

Research Notes

Atomicorp WAF protections are designed around attack techniques and exploit behaviors, allowing existing protections to apply across multiple vulnerabilities without requiring a unique rule for every CVE.

Public Vulnerability References

• NVD (opens in a new tab)
• CVE Record (opens in a new tab)
• CVE authority reference: https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/ (opens in a new tab)
• CVE authority reference: https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-os-command-injection-via-setdevice (opens in a new tab)

Test or Research Source

• Source: Atomicorp AI Research Framework
• Tags: cve, derived, rce, waf-probe

Research Note Context

This research note documents exploit-technique analysis associated with this vulnerability and references Atomicorp WAF protections observed during engineering review, testing, or validation activities.

Atomicorp security controls are generally designed to identify and mitigate attack techniques and exploit behaviors rather than individual CVE identifiers. As a result, protections developed for one vulnerability may also apply to related attack variants and future vulnerabilities using similar techniques.

Learn More

Atomicorp develops commercially supported security technologies for web applications, servers, endpoints, workloads, and legacy enterprise platforms.

Organizations interested in protecting systems against exploit techniques associated with vulnerabilities such as this one can learn more about:

• Atomic ModSecurity Rules: commercially maintained WAF rules for ModSecurity deployments, including protections for web attacks, bots, scanners, malware, exploitation attempts, and emerging vulnerability classes.
• Atomic WAF: an enterprise web application firewall with Atomicorp rules, centralized management, reporting, authentication controls, and operational tooling.
• Atomic ModSecurity Integrator: a special licensing option for MSPs, MSSPs, OEMs, VARs, reverse proxy providers, and other integrators who want to incorporate Atomicorp ModSecurity rule technology into their own products or services.
• Atomic OSSEC: an enterprise OSSEC-based intrusion detection, compliance, and security monitoring platform.
• Atomic Protector: workload protection for Linux, web, cloud, data center, and hybrid environments.

For additional information, product evaluations, or technical discussions, visit https://www.atomicorp.com/ or https://modsecurity.io/ (opens in a new tab) .