Cyber Resilience

CVE-2026-34271

DoS in Oracle Mysql Server 8.0.0 – 8.0.45

Published
21 April 2026
Modified
23 April 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0030 23th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-34271 is a medium-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Oracle Mysql Server. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 23th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-6 (Least Privilege) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Group Replication Plugin). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows low privileged attacker with network access via multiple protocols to compromise MySQL…

more

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 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).

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Remote network exploitation of MySQL server component directly enables application/system DoS via crafted requests (T1499.004); maps to public-facing app exploitation (T1190) and remote service exploitation (T1210).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-21950Same product: Oracle Mysql Server
CVE-2026-34304Same product: Oracle Mysql Server
CVE-2026-34278Same product: Oracle Mysql Server
CVE-2026-21998Same product: Oracle Mysql Server
CVE-2026-34308Same product: Oracle Mysql Server
CVE-2026-34270Same product: Oracle Mysql Server
CVE-2026-22009Same product: Oracle Mysql Server
CVE-2026-34303Same product: Oracle Mysql Server
CVE-2026-21948Same product: Oracle Mysql Server
CVE-2026-22004Same product: Oracle Mysql Server

Affected Assets

oracle
mysql server
8.0.0 — 8.0.45 · 8.4.0 — 8.4.8 · 9.0.0 — 9.6.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-5 Denial-of-service Protection
  • AC-6 Least Privilege
  • CM-7 Least Functionality
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly implements protections against resource-exhaustion DoS attacks that produce the availability impact described in this CVE.

prevent

Limits the actions available to the low-privileged network attacker, reducing the ability to trigger uncontrolled resource consumption via the Group Replication Plugin.

prevent

Disables or restricts the Group Replication Plugin (and other unneeded MySQL components) so the attack surface leading to CWE-400 is minimized.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

PR.IR-03 partial match
prevents

Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.

PR.PS-01 partial match
prevents

Hardened configuration baselines can include resource quotas and limits that constrain consumption.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

prevents

By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.

detects

Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.

mitigates

Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.

mitigates

Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.

detects

Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.

References