CVE-2026-4227
Published: 16 March 2026
Summary
CVE-2026-4227 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Lb-Link Bl-Wr9000 Firmware. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 33.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly validates inputs to the vulnerable /goform/get_hidessid_cfg endpoint, preventing buffer overflow exploitation in sub_44D844.
Implements memory protections such as stack canaries, ASLR, and DEP to mitigate buffer overflow vulnerabilities like CWE-119 in the affected function.
Requires monitoring for publicly disclosed flaws like CVE-2026-4227 and remediating via patching, isolation, or replacement since no vendor fix is available.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in the router's web management interface (/goform/get_hidessid_cfg) enables remote exploitation by authenticated low-privilege users for arbitrary code execution, directly mapping to public-facing application exploitation (T1190), remote services exploitation (T1210), and privilege escalation (T1068).
NVD Description
A security vulnerability has been detected in LB-LINK BL-WR9000 2.4.9. The impacted element is the function sub_44D844 of the file /goform/get_hidessid_cfg. The manipulation leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed…
more
publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Deeper analysisAI
CVE-2026-4227 is a buffer overflow vulnerability affecting the LB-LINK BL-WR9000 router running firmware version 2.4.9. The issue resides in the function sub_44D844 within the file /goform/get_hidessid_cfg, which handles Hide SSID configuration requests. This flaw, associated with CWE-119, CWE-120, and CWE-125, allows improper memory operations that can be triggered remotely. The vulnerability was published on 2026-03-16 and carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.
Attackers with network access and low privileges, such as authenticated users on the device, can exploit this vulnerability remotely without user interaction. By manipulating requests to the affected endpoint, adversaries can trigger the buffer overflow, potentially leading to arbitrary code execution, data corruption, or denial of service. The high confidentiality, integrity, and availability impacts suggest successful exploitation could grant full control over the device.
Advisories from VulDB and a public GitHub disclosure detail the vulnerability but note no response from the vendor despite early notification. No patches or mitigations are available from LB-LINK, leaving affected devices exposed. Security practitioners should isolate or replace vulnerable routers, monitor for anomalous traffic to the /goform/get_hidessid_cfg endpoint, and apply network segmentation.
The exploit has been publicly disclosed and may be actively used, increasing the risk for unpatched LB-LINK BL-WR9000 deployments in home or small office environments.
Details
- CWE(s)