Oracle MySQL Server up to 8.0.45/8.4.8/9.6.0 Optimizer denial of service

CVSS Meta Temp Score
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CTI Interest Score
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3.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Oracle MySQL Server up to 8.0.45/8.4.8/9.6.0. It has been rated as problematic. The impacted element is an unknown function of the component Optimizer. The manipulation leads to denial of service. This vulnerability is listed as CVE-2026-21998. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Oracle MySQL Server up to 8.0.45/8.4.8/9.6.0 and classified as problematic. This issue affects an unknown function of the component Optimizer. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. 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).

The advisory is shared at oracle.com. The identification of this vulnerability is CVE-2026-21998 since 01/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are necessary for exploitation. 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 316818 (RHEL 10 : mysql8.4 (RHSA-2026:20693)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (316818). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.8
VulDB Meta Temp Score: 3.7

VulDB Base Score: 2.7
VulDB Temp Score: 2.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.9
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: 316818
Nessus Name: RHEL 10 : mysql8.4 (RHSA-2026:20693)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/05/2026 CVE reserved
04/22/2026 +106 days Advisory disclosed
04/22/2026 +0 days VulDB entry created
05/28/2026 +36 days VulDB entry last update

Sourcesinfo

Vendor: oracle.com

Advisory: oracle.com
Status: Confirmed

CVE: CVE-2026-21998 (🔒)
GCVE (CVE): GCVE-0-2026-21998
GCVE (VulDB): GCVE-100-358673

Entryinfo

Created: 04/22/2026 06:52
Updated: 05/28/2026 21:29
Changes: 04/22/2026 06:52 (64), 05/28/2026 21:29 (2)
Complete: 🔍
Cache ID: 216::103

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

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