Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticate with high-privilege MySQL account
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DeliveryConnect over supported protocol
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ExploitSubmit crafted query hitting Optimizer
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ExecutionTrigger hang or repeatable crash
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ImpactComplete database DOS
Vulnerability Assessment
| Exploitation Conditions | Exploitation requires an authenticated, high-privileged MySQL account (CVSS PR:H) with network reachability to the server over one of MySQL's supported protocols; the attacker then sends a crafted query that triggers a defect in the Server: Optimizer query-planning component, causing a hang or repeatable crash. Limiting factors: the high-privilege account requirement excludes unauthenticated and least-privilege/application users, there is no confidentiality or integrity impact, and affected versions are specific (MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1). No special non-default configuration or user interaction is required beyond holding privileged credentials. |
| Impact | This is a moderate, availability-only issue (CVSS 3.1 4.9, vector AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H) whose real-world risk is substantially capped by its privilege requirement. The vector cleanly supports a network-reachable, low-complexity attack with no user interaction, but PR:H means the attacker must already hold a high-privileged MySQL account, which excludes anonymous remote actors and most least-privilege application accounts. Impact is confined to availability (complete DOS via hang or repeatable crash); there is no confidentiality or integrity loss. No EPSS score, CISA KEV listing, POC, or SSVC decision data was provided in the input, so exploitation likelihood cannot be quantified from these sources - consistent with no public exploit identified at time of analysis. Oracle's own text calls it 'easily exploitable,' which aligns with AC:L, but 'easily exploitable' refers to technical ease once the privilege precondition is met, not to ease of obtaining that privilege. Net: a legitimate patch-management priority on multi-tenant or shared database servers where privileged accounts are numerous or semi-trusted, but a low-urgency, contain-via-least-privilege issue on single-tenant deployments. Severity classification should not be inflated beyond the availability-only, high-privilege reality. |
| Exploit ScenarioDerived | An attacker possessing a high-privileged MySQL account (e.g., a semi-trusted DBA on a shared/multi-tenant server) connects over the network via one of the supported protocols and submits a specially crafted query that exercises a flaw in the Server: Optimizer component. The malformed optimization path causes the server to hang or repeatedly crash, producing a complete denial of service for all tenants/applications. No public exploit code was identified in the provided data. |
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Alert meAnalysisAIv1 – Oct 21, 2026
High-privileged MySQL accounts can hang or repeatedly crash MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, and 26.7.0-26.7.1, as well as MySQL Cluster 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3, and 26.7.0-26.7.1, by sending crafted queries that trigger a defect in the Server: Optimizer component, producing availability-only denial of service (CVSS 3.1 4.9). Exploitation requires an authenticated, high-privileged account (PR:H) with network reachability and no user interaction; confidentiality and integrity are unaffected. No public exploit identified at time of analysis.
RemediationAI
Apply the Oracle MySQL fix referenced in the October 2026 Critical Patch Update advisory at https://www.oracle.com/security-alerts/cpuoct2026.html; the provided data does not include exact patched version numbers, so use the advisory's fixed-version mapping for each affected branch (MySQL Server 8.4, 9.7, and 26.7; MySQL Cluster 8.0, 8.4, 9.7, and 26.7). Until the upgrade is complete, restrict network reachability to MySQL listeners and supported protocols to trusted hosts, and tightly limit who holds high-privilege accounts capable of exercising the optimizer, accepting that this reduces exposure without removing the flaw. Because the impact is crash/hang, monitor for repeated server restarts or optimizer-related hangs and use existing high-availability failover procedures; no non-default configuration workaround is identified in the provided data.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
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Technical ContextAI · show details
The issue sits in Oracle MySQL's Server: Optimizer component, the query-planning subsystem shared by MySQL Server and MySQL Cluster deployments. A high-privileged database account can submit crafted SQL over MySQL's supported network protocols, causing the optimizer to enter a state that hangs the service or triggers a repeatable crash; the CVSS vector (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H) reflects network reachability, low attack complexity, high privilege requirements, and availability-only impact. No CWE was provided, so the precise root-cause class is not confirmed from the input data; the affected component and impact indicate a query-planning/optimizer defect rather than a memory-safety or privilege-escalation flaw. The privilege requirement is the primary limiting factor: unauthenticated and least-privilege application users are excluded, and no confidentiality or integrity loss is associated with successful exploitation.
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Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Network-reachable, low-complexity crafted query but requires a high-privileged database account (PR:H); impact is availability-only DoS with no confidentiality or integrity loss and no scope change.
Primary rating from NVD.
CVSS VectorNVD
DescriptionNVD
Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and 26.7.0-26.7.1. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server, MySQL Cluster. 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).
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Oracle MySQL through 5.5.52, 5.6.x through 5.6.33, and 5.7.x through 5.7.15; MariaDB before 5.5.51, 10.0.x before 10.0.2
MySQL 5.5.19 and possibly other versions, and MariaDB 5.5.28a and possibly other versions, when configured to assign the
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Pluggable Auth). Rated high severity
sql/password.c in Oracle MySQL 5.1.x before 5.1.63, 5.5.x before 5.5.24, and 5.6.x before 5.6.6, and MariaDB 5.1.x befor
In Spring Framework, versions 5.2.x prior to 5.2.3, versions 5.1.x prior to 5.1.13, and versions 5.0.x prior to 5.0.16,
Heap-based buffer overflow in Oracle MySQL 5.5.19 and other versions through 5.5.28, and MariaDB 5.5.28a and possibly ot
Stack-based buffer overflow in the acl_get function in Oracle MySQL 5.5.19 and other versions through 5.5.28, and 5.1.53
Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due
mysqld_safe in Oracle MySQL through 5.5.51, 5.6.x through 5.6.32, and 5.7.x through 5.7.14; MariaDB; Percona Server befo
Oracle MySQL before 5.7.3, Oracle MySQL Connector/C (aka libmysqlclient) before 6.1.3, and MariaDB before 5.5.44 use the
HUSTOJ online judge has a path traversal vulnerability enabling arbitrary file access on the competition server.
Integer overflow in the EVP_EncodeUpdate function in crypto/evp/encode.c in OpenSSL before 1.0.1t and 1.0.2 before 1.0.2
EUVD-2026-106018
GHSA-rvrp-m6p5-gg33
NVD
CVE.org
EPSS
Exploit-DB