Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-120240 Overview
A vulnerability was determined in WAVLINK WN553X1-B V260403_2.0.0. This issue affects the function sub_41A748 of the file /bin/ioos of the component WireGuard CLI Group Handler. Executing a manipulation of the argument group_id/group_name can lead to os command injection. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure.
Critical Impact
Affected Products
- WAVLINK WN553X1-B: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-01: CVE-2026-120240 published to the National Vulnerability Database by cna@vuldb.com
- 2026-11-01: last updated in the NVD database
Technical Details for CVE-2026-120240
Vulnerability Analysis
CVE-2026-120240 is a Command Injection weakness (CWE-77: Command Injection, CWE-78: OS Command Injection) in WAVLINK WN553X1-B. Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Untrusted input ends up inside a system command.
With a CVSS base score of 8.6, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The weakness is classified as CWE-77: Command Injection, CWE-78: OS Command Injection. Untrusted input ends up inside a system command.
Attack Vector
Based on the CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/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
Detection Methods for CVE-2026-120240
Detection Strategies
- Inventory every instance of WAVLINK WN553X1-B and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward WAVLINK WN553X1-B application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-120240
Immediate Actions Required
- Apply the fixed version of WAVLINK WN553X1-B named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for WAVLINK WN553X1-B.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
- CWE-77: Command Injection More CVEs with this weakness
- CWE-78: OS Command Injection More CVEs with this weakness
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
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