# CVE-2026-120240: WAVLINK WN553X1-B WireGuard command injection

Source: https://junglewise.ai/threats/cve-2026-120240-a-vulnerability-was-determined-in-wavlink-wn553x1-b-v260403-2-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-01. Updated: 2026-11-01  
License: CC BY 4.0 with a link back

CVE-2026-120240 · Severity: critical · CVSS 9.9 · Published 2026-11-01

The WAVLINK WN553X1-B router manages VPN connections via a web-based control panel. An authenticated attacker can inject arbitrary operating system commands through the WireGuard group management interface, gaining complete control of the device as root. Factory-default credentials that are never changed eliminate the authentication barrier on most affected devices.

Technologies: [Wavlink WN553X1-B](https://junglewise.ai/threats/technologies/wn553x1-b). Vendors: [Wavlink](https://junglewise.ai/threats/vendors/wavlink).

## Quick answers

**Is CVE-2026-120240 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120240 being exploited in the wild.

**How severe is CVE-2026-120240?** Critical severity, with a CVSS score of 9.9, published 1 November 2026.

**Which products and versions are affected?** Wavlink WN553X1-B V260403_2.0.0.

**Is there a fix for CVE-2026-120240?** No fixed version is recorded yet. Change the default admin password immediately and restrict HTTP access to the device management interface (port 81) to trusted networks only. Disable the WireGuard CLI group feature if not in use. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-120240 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-120240?** Check whether you run Wavlink WN553X1-B 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.

## How to fix


Change the default admin password immediately and restrict HTTP access to the device management interface (port 81) to trusted networks only. Disable the WireGuard CLI group feature if not in use.

## Technical details

A command injection vulnerability exists in the /bin/ioos binary's WireGuard CLI group handler, specifically in the sub_41A748 function handling the group_id and group_name parameters. User input is passed unsanitized to the system() function via snprintf without validation, allowing attackers to break out of single-quoted strings and inject arbitrary commands. Successful exploitation requires an authenticated session; however, factory-default credentials are hardcoded on most devices.

## Affected products

- WAVLINK WN553X1-B V260403_2.0.0

## Timeline

- 2026-11-01: disclosed: Public disclosure via GitHub
- 2026-11-01: advisory

## References

- [https://github.com/senxitoyshuyi-ui/HACKALL/blob/main/WAVLINK%20WN553X1-B%20Router/WAVLINK_WN553X1-B_wireguard_cli_group_command_injection.md](https://github.com/senxitoyshuyi-ui/HACKALL/blob/main/WAVLINK%20WN553X1-B%20Router/WAVLINK_WN553X1-B_wireguard_cli_group_command_injection.md)
- [https://vuldb.com/cve/CVE-2026-120240](https://vuldb.com/cve/CVE-2026-120240)

## Related threats

- [WAVLINK WN553X1-B WireGuard CLI command injection](https://junglewise.ai/threats/cve-2026-120239-a-vulnerability-was-found-in-wavlink-wn553x1-b-v260403-2-0-0)
- [WAVLINK WN553X1-B command injection in ovpn_file handler](https://junglewise.ai/threats/cve-2026-120238-a-vulnerability-has-been-found-in-wavlink-wn553x1-b-260403-2-0-0)
- [WAVLINK WN553X1-B OS command injection in OpenVPN CLI handler](https://junglewise.ai/threats/cve-2026-120231-a-vulnerability-was-determined-in-wavlink-wn553x1-b-v260403-2-0)
- [WAVLINK WN553X1-B os command injection in ioos](https://junglewise.ai/threats/cve-2026-120229-a-vulnerability-has-been-found-in-wavlink-wn553x1-b-260403-2-0-0)
- [WAVLINK WN553X1-B command injection in ioos service](https://junglewise.ai/threats/cve-2026-120228-a-flaw-has-been-found-in-wavlink-wn553x1-b-v260403-2-0-0-this)