# CVE-2026-71943: DrayTek VigorSwitch command injection in setDevNet

Source: https://junglewise.ai/threats/cve-2026-71943-draytek-vigorswitch-command-injection-in-setdevnet  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-71943 · Severity: high · CVSS 7.2 · Published 2026-08-24

DrayTek VigorSwitch is a network switching appliance used in enterprise environments to manage and route network traffic. The vulnerable setDevNet function fails to properly sanitize user-supplied input in administrative credentials, allowing an authenticated attacker with valid admin access to inject arbitrary shell commands that execute with root-level privileges, potentially compromising the entire network infrastructure managed by the switch.

Technologies: [DrayTek VigorSwitch FX2120](https://junglewise.ai/threats/technologies/vigorswitch-fx2120), [DrayTek VigorSwitch G1280](https://junglewise.ai/threats/technologies/vigorswitch-g1280), [DrayTek VigorSwitch G1282](https://junglewise.ai/threats/technologies/vigorswitch-g1282), [DrayTek VigorSwitch G2100](https://junglewise.ai/threats/technologies/vigorswitch-g2100), [DrayTek VigorSwitch G2121](https://junglewise.ai/threats/technologies/vigorswitch-g2121), [DrayTek VigorSwitch G2280x](https://junglewise.ai/threats/technologies/vigorswitch-g2280x), [DrayTek VigorSwitch G2282x](https://junglewise.ai/threats/technologies/vigorswitch-g2282x), [DrayTek VigorSwitch G2540x](https://junglewise.ai/threats/technologies/vigorswitch-g2540x), [DrayTek VigorSwitch G2540xs](https://junglewise.ai/threats/technologies/vigorswitch-g2540xs), [DrayTek VigorSwitch G2542x](https://junglewise.ai/threats/technologies/vigorswitch-g2542x), [DrayTek VigorSwitch P1280](https://junglewise.ai/threats/technologies/vigorswitch-p1280), [DrayTek VigorSwitch P1281x](https://junglewise.ai/threats/technologies/vigorswitch-p1281x), [DrayTek VigorSwitch P1282](https://junglewise.ai/threats/technologies/vigorswitch-p1282), [DrayTek VigorSwitch P2100](https://junglewise.ai/threats/technologies/vigorswitch-p2100), [DrayTek VigorSwitch P2121](https://junglewise.ai/threats/technologies/vigorswitch-p2121), [DrayTek VigorSwitch P2280x](https://junglewise.ai/threats/technologies/vigorswitch-p2280x), [DrayTek VigorSwitch P2282x](https://junglewise.ai/threats/technologies/vigorswitch-p2282x), [DrayTek VigorSwitch P2540x](https://junglewise.ai/threats/technologies/vigorswitch-p2540x), [DrayTek VigorSwitch P2540xs](https://junglewise.ai/threats/technologies/vigorswitch-p2540xs), [DrayTek VigorSwitch P2542x](https://junglewise.ai/threats/technologies/vigorswitch-p2542x), [DrayTek VigorSwitch P2542xh](https://junglewise.ai/threats/technologies/vigorswitch-p2542xh), [DrayTek VigorSwitch PQ2121x](https://junglewise.ai/threats/technologies/vigorswitch-pq2121x), [DrayTek VigorSwitch PQ2200xb](https://junglewise.ai/threats/technologies/vigorswitch-pq2200xb), [DrayTek VigorSwitch PQ2300xb](https://junglewise.ai/threats/technologies/vigorswitch-pq2300xb), [DrayTek VigorSwitch PX2060](https://junglewise.ai/threats/technologies/vigorswitch-px2060), [DrayTek VigorSwitch Q2121x](https://junglewise.ai/threats/technologies/vigorswitch-q2121x), [DrayTek VigorSwitch Q2200x](https://junglewise.ai/threats/technologies/vigorswitch-q2200x), [DrayTek VigorSwitch Q2300x](https://junglewise.ai/threats/technologies/vigorswitch-q2300x). Vendors: [DrayTek](https://junglewise.ai/threats/vendors/draytek).

## Quick answers

**Is CVE-2026-71943 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-71943 being exploited in the wild.

**How severe is CVE-2026-71943?** High severity, with a CVSS score of 7.2, published 24 August 2026.

**Which products and versions are affected?** DrayTek VigorSwitch FX2120 before 3.9.10; DrayTek VigorSwitch G1280 before 2.9.10; DrayTek VigorSwitch G1282 before 2.9.10; DrayTek VigorSwitch G2100 before 2.9.10; and 24 more.

**Is there a fix for CVE-2026-71943?** A patch was published on 2026-08-24. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-71943 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-71943?** Check whether you run DrayTek VigorSwitch FX2120, DrayTek VigorSwitch G1280, DrayTek VigorSwitch G1282 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This is an OS command injection vulnerability (CWE-78) in the setDevNet function within the mainfunction.cgi component of multiple DrayTek VigorSwitch firmware versions. The root cause is insufficient input validation and filtering of the username and password fields before they are passed to command execution routines. An authenticated attacker with valid administrative credentials can craft malicious input containing shell metacharacters to break out of the intended command context and execute arbitrary OS commands with root privileges on the affected device. Exploitation is network-accessible but requires valid admin credentials and authentication to the web management interface. Patches are available in the specified firmware versions for each model.

## Affected products

- DrayTek VigorSwitch G2540xs before 3.9.10
- DrayTek VigorSwitch P2540xs before 3.9.10
- DrayTek VigorSwitch FX2120 before 3.9.10
- DrayTek VigorSwitch G2282x before 2.10.6
- DrayTek VigorSwitch P2282x before 2.10.6
- DrayTek VigorSwitch Q2300x before 2.10.7
- DrayTek VigorSwitch PQ2300xb before 2.10.7
- DrayTek VigorSwitch G2542x before 3.10.6
- DrayTek VigorSwitch P2542x before 3.10.6
- DrayTek VigorSwitch P2542xh before 3.10.6
- DrayTek VigorSwitch PX2060 before 2.9.10
- DrayTek VigorSwitch G1280 before 2.9.10
- DrayTek VigorSwitch P1280 before 2.9.10
- DrayTek VigorSwitch P1281x before 2.9.10
- DrayTek VigorSwitch G1282 before 2.9.10
- DrayTek VigorSwitch P1282 before 2.9.10
- DrayTek VigorSwitch G2121 before 2.9.10
- DrayTek VigorSwitch P2121 before 2.9.10
- DrayTek VigorSwitch PQ2121x before 2.9.10
- DrayTek VigorSwitch Q2121x before 2.9.10
- DrayTek VigorSwitch G2280x before 2.9.10
- DrayTek VigorSwitch P2280x before 2.9.10
- DrayTek VigorSwitch Q2200x before 2.9.10
- DrayTek VigorSwitch PQ2200xb before 2.9.10
- DrayTek VigorSwitch G2100 before 2.9.10
- DrayTek VigorSwitch P2100 before 2.9.10
- DrayTek VigorSwitch G2540x before 2.9.10
- DrayTek VigorSwitch P2540x before 2.9.10

## Timeline

- 2026-08-24: disclosed
- 2026-08-24: patched

## References

- [https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/](https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/)
- [https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-os-command-injection-via-setdevnet](https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-os-command-injection-via-setdevnet)

## Related threats

- [DrayTek VigorSwitch buffer overflow in mail_mailalert](https://junglewise.ai/threats/cve-2026-71942-draytek-vigorswitch-buffer-overflow-in-mail-mailalert)
- [DrayTek VigorSwitch buffer overflow in diag_logmail](https://junglewise.ai/threats/cve-2026-71941-draytek-vigorswitch-buffer-overflow-in-diag-logmail)
- [DrayTek VigorSwitch buffer overflow in acl_general_setup Edit ACE](https://junglewise.ai/threats/cve-2026-71940-draytek-vigorswitch-buffer-overflow-in-acl-general-setup-edit-ace)
- [DrayTek VigorSwitch buffer overflow in acl_general_setup](https://junglewise.ai/threats/cve-2026-71939-draytek-vigorswitch-buffer-overflow-in-acl-general-setup)
- [DrayTek VigorSwitch buffer overflow in switch_lan_gvrp](https://junglewise.ai/threats/cve-2026-71938-draytek-vigorswitch-buffer-overflow-in-switch-lan-gvrp)