Oracle MySQL Server up to 8.0.44/8.4.7/9.5.0 Optimizer denial of service

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Oracle MySQL Server up to 8.0.44/8.4.7/9.5.0. The affected element is an unknown function of the component Optimizer. This manipulation causes denial of service. This vulnerability appears as CVE-2026-21968. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Oracle MySQL Server up to 8.0.44/8.4.7/9.5.0. Affected by this vulnerability is an unknown code of the component Optimizer. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.0-8.0.44, 8.4.0-8.4.7 and 9.0.0-9.5.0. Easily exploitable vulnerability allows low 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 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).

The advisory is shared at oracle.com. This vulnerability is known as CVE-2026-21968 since 01/05/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 296583 (Oracle MySQL Server 8.4.x < 8.4.8 (January 2026 CPU)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (296583), EUVD (EUVD-2026-3544) and CERT Bund (WID-SEC-2026-0168). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • Oracle Linux
  • RESF Rocky Linux
  • Oracle MySQL

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (oracle): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 296583
Nessus Name: Oracle MySQL Server 8.4.x < 8.4.8 (January 2026 CPU)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/05/2026 CVE reserved
01/20/2026 +15 days Advisory disclosed
01/20/2026 +0 days VulDB entry created
03/25/2026 +64 days VulDB entry last update

Sourcesinfo

Vendor: oracle.com

Advisory: oracle.com
Status: Confirmed

CVE: CVE-2026-21968 (🔒)
GCVE (CVE): GCVE-0-2026-21968
GCVE (VulDB): GCVE-100-342073
EUVD: 🔒
CERT Bund: WID-SEC-2026-0168 - Oracle MySQL: Mehrere Schwachstellen

Entryinfo

Created: 01/20/2026 23:44
Updated: 03/25/2026 07:01
Changes: 01/20/2026 23:44 (64), 01/21/2026 08:26 (1), 01/26/2026 22:15 (2), 03/25/2026 07:01 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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