CyberSecBulletin
CVE-2026-120240NVD status: Deferred

WN553X1-B: Improper Neutralization of Special Elements used in a Command

CVE-2026-120240 is a critical-severity improper neutralization of special elements used in a command vulnerability in WN553X1-B from WAVLINK, with a CVSS 3.1 base score of 9.9 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected WN553X1-B versions: V260403_2.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.69% chance of exploitation within 30 days, higher than 77% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of WN553X1-B you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
WAVLINKWN553X1-BV260403_2.0.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (vuldb.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.6HighCNA (vuldb.com)
CVSS 3.19.9CriticalCNA (vuldb.com)
CVSS 2.09.0HighCNA (vuldb.com)

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Special Elements used in a Command

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • If possible, ensure that all external commands called from the program are statically created.
  • Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.

More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in WN553X1-B

All WN553X1-B vulnerabilities

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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