VulnerabilityPublished 16 Mar 2026

CVE-2026-4228: LB-LINK BL-WR9000 · Command Injection

Affects LB-LINK BL-WR9000Source CVE Database V5

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Public exploit available · 12% EPSS · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 12.6% chance of exploitation in 30 days – higher than 96% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
LB-LINKBL-WR9000	Affected =2.4.9	Fixed in–

AI-suggested

Immediately isolate affected LB-LINK BL-WR9000 devices from untrusted networks to prevent remote exploitation.
Disable remote management interfaces and Wi-Fi configuration endpoints if possible to reduce attack surface.
Monitor network traffic for unusual activity or command execution attempts targeting /goform/set_wifi.
Implement network segmentation to limit the impact of a compromised device.
Use firewall rules to restrict access to the router’s management interfaces to trusted IP addresses only.
7. Consider replacing affected devices with models from vendors with active security support if mitigation is not feasible. 8. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect command injection patterns targeting this vulnerability. 9. Educate users about the risks of using outdated or unsupported network devices. 10. Maintain comprehensive backups of router configurations to enable rapid recovery if compromise occurs.

Description

A vulnerability was detected in LB-LINK BL-WR9000 2.4.9. This affects the function sub_458754 of the file /goform/set_wifi. The manipulation results in command injection. It is possible to launch the attack remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

The exploitation of CVE-2026-4228 can lead to unauthorized remote command execution on affected LB-LINK BL-WR9000 devices. This can compromise the confidentiality, integrity, and availability of the device and potentially the entire network it supports. Attackers may alter router configurations, intercept or redirect network traffic, deploy malware, or create persistent backdoors. For organizations, this could result in data breaches, network downtime, and loss of trust. Since the router is often deployed in small to medium business and home environments, the impact could extend to sensitive personal or business data. The public availability of exploit code increases the likelihood of opportunistic attacks, especially against unpatched or unmanaged devices. The absence of vendor patches exacerbates the risk, making mitigation and detection critical to prevent exploitation.

Summary

CVE-2026-4228 is a medium-severity command injection vulnerability affecting the LB-LINK BL-WR9000 wireless router running firmware version 2.4.9. The vulnerability is located in the function sub_458754 within the /goform/set_wifi endpoint, which handles Wi-Fi configuration settings. Due to insufficient input sanitization, an attacker can inject malicious commands remotely without requiring authentication or user interaction. This allows execution of arbitrary commands with the privileges of the affected service, potentially leading to device compromise, unauthorized configuration changes, or pivoting within the network. The vulnerability was responsibly disclosed to the vendor, who has not issued any response or patch. The exploit code is publicly available, increasing the risk of exploitation by threat actors. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, no user interaction, and partial impact on confidentiality, integrity, and availability. The lack of vendor response and patch availability means affected organizations must rely on alternative mitigation strategies until an official fix is released.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Mar 2026, 08:35 UTC

Technical details

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