LiveActive security incident?Get immediate response
CVE Record

CVE-2021-35647: Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer).

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.26 and prior. 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).

MediumCVSS 4.9Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This MySQL Server flaw can let an already high-privileged user with network access crash or hang the database. The main business risk is outage, not data theft or tampering. Because exploitation requires high privileges, urgency depends on where MySQL is exposed and how tightly privileged accounts are controlled.

Executive priority

Treat this as a service-availability risk. It is less urgent than unauthenticated remote code execution, but production databases on affected versions should be patched through normal vulnerability SLAs, faster where privileged access is broad or internet-adjacent.

Technical view

CVE-2021-35647 affects Oracle MySQL Server 8.0.26 and prior in the Server Optimizer component. The CVSS vector is AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H, meaning remote network reachability is relevant, but successful abuse requires high privileges and causes complete denial of service.

Likely exposure

Organizations running MySQL Server 8.0.26 or earlier are potentially exposed, especially where privileged database users can connect over network protocols. NetApp also published related advisory coverage, so embedded or bundled MySQL use should be checked against vendor notices.

Exploitation context

The provided sources do not show CISA KEV listing or confirmed active exploitation. The vulnerability is described as easily exploitable after obtaining high privileges, with impact limited to database availability through hangs or repeatable crashes.

Researcher notes

Evidence is limited to CVE data, Oracle CPU reference, and NetApp advisory reference. No CWE, exploit details, or precise fixed MySQL version are provided in the bundle. Validation should focus on version inventory, vendor patch status, privilege exposure, and database availability telemetry.

Mitigation direction

  • Apply Oracle's October 2021 Critical Patch Update or later MySQL Server vendor guidance.
  • Inventory MySQL Server versions and prioritize any 8.0.26 or earlier deployments.
  • Restrict MySQL network access to trusted hosts and administrative paths.
  • Review and reduce high-privilege database accounts where operationally feasible.
  • Check NetApp advisory coverage for affected appliances or bundled software.

Validation and detection

  • Confirm each MySQL instance version is later than the affected 8.0.26-and-prior range.
  • Verify Oracle CPU or downstream vendor fixes are installed in production and backups.
  • Review firewall and security group rules for MySQL listener exposure.
  • Audit high-privilege MySQL accounts with network login capability.
  • Check monitoring history for unexplained MySQL hangs or repeated crashes.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-35647 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
4.9CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H1.23.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.9Medium
CVSS 3.1 vector shape for CVE-2021-35647Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Oracle CorporationMySQL Server8.0.26 and priorListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.