Oracle MySQL Server up to 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 was found in Oracle MySQL Server up to 9.5.0. It has been rated as problematic. This affects an unknown part of the component Optimizer. Performing a manipulation results in denial of service. This vulnerability is cataloged as CVE-2026-21949. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Oracle MySQL Server up to 9.5.0. It has been classified as problematic. This affects an unknown function of the component Optimizer. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 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 uniquely identified as CVE-2026-21949 since 01/05/2026. The exploitability is told to be easy. It is possible to initiate the attack 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 296582 (Oracle MySQL Server 9.x.x < 9.6.0 (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 (296582), EUVD (EUVD-2026-3560) and CERT Bund (WID-SEC-2026-0168). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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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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: 296582
Nessus Name: Oracle MySQL Server 9.x.x < 9.6.0 (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
03/24/2026 +63 days VulDB entry last update

Sourcesinfo

Vendor: oracle.com

Advisory: oracle.com
Status: Confirmed

CVE: CVE-2026-21949 (🔒)
GCVE (CVE): GCVE-0-2026-21949
GCVE (VulDB): GCVE-100-342069
EUVD: 🔒
CERT Bund: WID-SEC-2026-0168 - Oracle MySQL: Mehrere Schwachstellen

Entryinfo

Created: 01/20/2026 23:43
Updated: 03/24/2026 22:19
Changes: 01/20/2026 23:43 (64), 01/21/2026 10:57 (1), 01/26/2026 22:15 (2), 03/24/2026 22:19 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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