Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessObtain high-privilege MySQL account
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DeliveryConnect over network protocol
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ExploitSubmit crafted query to Optimizer
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ExecutionTrigger hang or repeatable crash
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ImpactComplete denial of service
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK
1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires an authenticated session holding HIGH database privileges on MySQL Server or MySQL Cluster (CVSS PR:H), reachable over the network via one of multiple supported MySQL protocols; the malicious input is processed by the Server's Optimizer component. No user interaction is needed and attack complexity is low, so once privileged access exists the crash is reliably repeatable. The primary limiting factor is the high-privilege prerequisite - unprivileged or read-only users cannot trigger it - which confines realistic exploitation to trusted administrators, service accounts, or an attacker who has already captured privileged credentials. Affected versions: 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. |
| Impact | This is a moderate-severity, availability-only vulnerability (CVSS 3.1 base 4.9) whose real-world risk is substantially constrained by its privilege requirement. The CVSS vector (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H) shows network-reachable, low-complexity exploitation with no user interaction, but PR:H means the attacker must already hold high database privileges, which sharply limits the threat population to trusted/administrative accounts or a compromised privileged credential. Impact is limited to a hang or repeatable crash (complete DoS) of the Server; there is no confidentiality or integrity impact (C:N/I:N). No EPSS score, SSVC decision data, or CVE-specific CWE was provided, so automatable/technical-impact framing cannot be derived. The input contains no KEV listing and no POC reference, so exploitation status is 'no public exploit identified at time of analysis.' Net assessment: despite affecting a ubiquitous product, this is a lower-priority issue relative to RCE or auth-bypass flaws - the high privilege prerequisite and availability-only scope make it a legitimate but non-urgent patch-cycle item rather than an emergency, best remediated via Oracle's October 2026 Critical Patch Update. |
| Exploit ScenarioDerived | An attacker who already possesses high-privilege MySQL credentials (e.g., a malicious insider, or an external attacker who has compromised an admin/service account) connects over the network via a supported protocol and issues a specially crafted query that the Server's Optimizer component mishandles, hanging or repeatably crashing the database and causing a complete denial of service. Because AC:L and UI:N, the crash is reliably triggerable once privileged access exists, but no public exploit code is identified at time of analysis. |
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Alert meAnalysisAIv1 – Oct 21, 2026
A denial-of-service flaw in the Oracle MySQL Server Optimizer also affects MySQL Cluster, allowing a high-privileged attacker with network access to hang or repeatedly crash the server (CVSS 3.1 base 4.9, availability-only). Affected releases are MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, and 26.7.0-26.7.1, plus 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. Exploitation requires an authenticated session holding HIGH database privileges (CVSS PR:H), which sharply limits exposure; no public exploit code or confirmed active exploitation was identified at time of analysis.
RemediationAI
Apply the Oracle Critical Patch Update referenced at https://www.oracle.com/security-alerts/cpuoct2026.html, which is the vendor's canonical channel for fixes; no exact fixed release number is stated in the supplied data, so confirm the post-CPU version for your branch (8.4.x, 9.7.x, or 26.7.x, and the corresponding MySQL Cluster NDB build) against the advisory before upgrading, and schedule the restart because mysqld and NDB data nodes must be bounced. Where patching is delayed, reduce exposure by ensuring only genuinely administrative accounts retain HIGH privileges such as SYSTEM_USER, restricting network reachability of the 3306/TCP and NDB ports to application and management subnets, and auditing privileged service accounts, since the flaw cannot be triggered by unprivileged or read-only users; these controls do not eliminate the bug and impose operational overhead on legitimate DBAs and automation. Rate-limiting or proxying privileged SQL sessions can blunt repeated crash attempts but may break legitimate long-running optimizer workloads, so validate in staging first.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The vulnerability resides in the Server: Optimizer component of Oracle MySQL, the query-planning subsystem that parses, rewrites, and selects execution strategies for SQL statements; MySQL Cluster (NDB) shares the same server-side optimizer code path. Because the weakness manifests when malformed or pathological statements are processed during optimization, an attacker able to submit arbitrary SQL through any of MySQL's supported network protocols can drive the optimizer into a state that hangs or crashes the mysqld process, causing complete denial of service. The CVSS 3.1 vector AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H confirms low-complexity, unauthenticated-at-the-network-layer exploitation but with a high-privilege prerequisite, no confidentiality or integrity impact, and no scope change. No CWE was assigned in the source data, so the precise root-cause class (for example, improper resource-lifetime handling or unbounded resource consumption in the optimizer) is not officially classified and must be derived from the vendor's CPU advisory.
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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 (AV:N) low-complexity (AC:L) crash requiring high DB privileges (PR:H), no interaction (UI:N), availability-only impact (A:H, C:N/I:N).
Primary rating from Vendor (oracle).
CVSS VectorVendor: oracle
DescriptionCVE.org
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
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
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-2026-106185
GHSA-p5pq-6f8g-x4w3
NVD
CVE.org
EPSS
Exploit-DB