CVE-2026-21964

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{"bugzilla": {"description": "mysql: Thread Pooling unspecified vulnerability (CPU Jan 2026)", "id": "2431431", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2431431"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["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)."], "name": "CVE-2026-21964", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "mysql8.4", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "mysql", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "mysql:8.0/mysql", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "mysql:8.4/mysql", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "mysql", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "mysql:8.4/mysql", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-01-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-21964\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-21964\nhttps://www.oracle.com/security-alerts/cpujan2026.html#AppendixMSQL"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Oracle MySQL Critical Patch Update.", "threat_severity": "Moderate"}

{"analysis": {"en": {"generated_at": "2026-04-18T15:37:58.818344+00:00", "value": {"mitigation_remediation": ["Install the Oracle security update for MySQL Server that fixes the Thread Pooling issue as detailed in the January\u202f2026 CPU advisory.", "Restrict inbound traffic to the MySQL port (default 3306) to trusted IP ranges or employ firewall rules to limit exposure to authorized hosts.", "Consider disabling or reducing thread pooling settings until a patched version is deployed, and monitor server health to restart the process promptly after crashes."], "summary": {"action": "Apply Patch", "impact": "Denial of Service"}, "threat_synthesis": {"affected_systems": "Affected versions include Oracle MySQL Server 8.0.0 through 8.0.44, 8.4.0 through 8.4.7, and 9.0.0 through 9.5.0. All installations of these versions that enable Thread Pooling are potentially vulnerable.", "description_and_impact": "The vulnerability lies in the Thread Pooling component of Oracle MySQL Server and allows a high privileged attacker with network access through various protocols to cause the database server to hang or repeatedly crash, resulting in a complete denial of service for legitimate users. The weakness can be inferred as uncontrolled resource consumption (CWE\u2011770).", "risk_and_exploitability": "The CVSS 3.1 base score of 4.9 indicates a moderate severity focused on availability; the EPSS score of less than 1\u202f% suggests that exploitation is unlikely at present, and the vulnerability is not listed in CISA\u2019s KEV catalog. The likelihood of exploitation in the wild is low, but the attack vector requires remote network connectivity and attacker privileges at the database level, which may be granted to application users in many environments. The primary risk is an availability outage that could impact business operations."}}}}, "created": "2026-04-18T15:45:04.272395+00:00", "updated": "2026-04-18T15:45:04.272406+00:00", "vendors": [], "weaknesses": ["CWE-770"]}