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MySQL Server CVE-2026-101725

| EUVDEUVD-2026-106126 MEDIUM
Improper Access Control (CWE-284)
2026-10-20 secalert_us@oracle.com GHSA-m942-vq33-2r23
6.5
CVSS 3.1 · Vendor: oracle
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Authenticate with low-privileged MySQL account
  2. Delivery
    Connect over network via supported protocol
  3. Exploit
    Send crafted request triggering C API fault
  4. Execution
    Server hangs or repeatably crashes
  5. Impact
    Complete 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 a valid low-privileged MySQL account (CVSS PR:L) with network reachability to the server over one of the supported client protocols; the flaw resides in the C API component of MySQL Server and MySQL Cluster. Affected builds are MySQL Server 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1 and 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. The primary limiting factor is the authentication requirement - unauthenticated attackers cannot trigger it - so risk is highest where low-privileged credentials are widely distributed (multi-tenant hosting, shared application databases) or where the database port is exposed beyond trusted networks. No user interaction or non-default configuration is indicated as a prerequisite.

Impact

This is a moderate-severity denial-of-service issue with a vendor-assigned CVSS 3.1 base score of 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). The vector signals favorable attacker conditions - network reachable, low attack complexity, no user interaction - but require low-level authentication (PR:L), which meaningfully constrains the attacker population to users who already hold valid MySQL credentials. Impact is confined to availability (A:H) with no confidentiality or integrity effect, so the realistic worst case is a hang or repeatable crash (complete DoS) rather than data compromise or code execution. No EPSS score, CISA KEV listing, or public proof-of-concept is present in the supplied data, and the issue is not in CISA KEV, so there is no confirmed active exploitation. Net assessment: this is a real but not top-tier priority - patch during normal Oracle Critical Patch Update cycles, prioritizing internet-exposed or multi-tenant MySQL instances where low-privileged accounts are broadly held. The 'easily exploitable' language in the Oracle description aligns with AC:L but should not be read as unauthenticated: the CVSS vector authoritatively requires PR:L.

Exploit ScenarioDerived

An attacker holding a low-privileged MySQL account (e.g., a tenant or application database user) connects over the network via one of the supported client protocols and issues a crafted request that triggers a fault in the C API handling path. The server hangs or crashes repeatably, producing a complete denial of service for all dependent applications. No public exploit code is identified at time of analysis, and no user interaction is required.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 21, 2026

Denial of service in Oracle MySQL Server (C API component) and MySQL Cluster allows an authenticated low-privileged attacker with network access to hang or repeatedly crash the database, causing complete availability loss. Affected branches include 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; CVSS 3.1 is 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). No public exploit was identified at time of analysis, and exploitation requires valid low-privileged credentials and network reachability.

RemediationAI

Apply the fixed MySQL Server or MySQL Cluster build published in Oracle's October 2026 Critical Patch Update (https://www.oracle.com/security-alerts/cpuoct2026.html) for the affected branch (8.4.x, 9.7.x, 26.7.x, or Cluster 8.0.x); patch availability is per the vendor advisory, and the exact fixed version should be confirmed from that CPU before rollout. Until patching is complete, reduce exposure by restricting network access to MySQL ports to trusted application and administrative hosts, eliminating broad internet exposure of database and Cluster ports, and enforcing least privilege so low-privileged accounts are not widely shared; the trade-off is that tighter firewall and account scoping can disrupt legitimate multi-tenant or remote-client access. Monitor for repeated server crashes, hangs, and abnormal connection patterns from low-privileged accounts, and consider connection rate limiting or temporary account lockout as containment controls; these do not remove the flaw and may affect legitimate high-volume clients.

Affected VersionsENISA

MySQL Server 8.4.0-8.4.12
MySQL Server 26.7.0-26.7.1
MySQL Cluster 8.0.0-8.0.49
MySQL Cluster 9.7.0-9.7.3
MySQL Cluster 8.4.0-8.4.12
MySQL Cluster 26.7.0-26.7.1
MySQL Server 9.7.0-9.7.3

Affected Packages

euvd mysql_cluster no fix
euvd mysql_server no fix

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 issue sits in the C API component shared by MySQL Server and MySQL Cluster. The assessed CVSS 3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H indicates a remotely reachable, low-complexity attack that requires only a low-privileged authenticated account and no user interaction; confidentiality and integrity are unaffected while availability is fully lost. No CWE was assigned in the supplied data, so the root cause is characterized by Oracle as a C API flaw that can be driven over multiple protocols to induce a hang or repeatable crash. The independent assessment notes no non-default configuration prerequisite, meaning standard deployments in the affected version ranges are in scope; the main barrier is obtaining valid low-privilege credentials, making shared-hosting, multi-tenant, and network-exposed database deployments higher risk.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (oracle) PRIMARY 6.5 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vuln.today AI 6.5 MEDIUM

Network-reachable over multiple protocols (AV:N, AC:L) but requires a low-privileged authenticated account (PR:L); impact is availability-only (A:H) with no confidentiality or integrity effect.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Red Hat 6.5 MEDIUM

Primary rating from Vendor (oracle).

CVSS VectorVendor: oracle

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: C API). 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 low 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 6.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Threat Intelligence Overview

EPSS Score
0.4%
Top 66% exploitable
Prevalence
Ubiquitous
MySQL is among the most widely deployed databases worldwide
Data Quality
4 sources
Confidence: Medium

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.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

32
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +32
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Vendor StatusVendor

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