CVE-2026-4227
Memory Safety in Lb-Link Bl-Wr9000 Firmware 2.4.9
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
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 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 49th 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 map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-12369
Vulnerability Data
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V17.3.2V5.2.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can find missing size checks before deployment.
Input validation directly enforces size checks before buffer copies.
Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.
Vulnerability scanning and code analysis directly surface buffer-boundary flaws.
Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.
Developer training on secure coding reduces introduction of memory-buffer errors.
Patching replaces vulnerable code containing buffer-boundary defects.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.
Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.
Application security requirements can specify memory-safety rules, but do not prescribe implementation details.
Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.