CVE-2026-21950 is a medium severity vulnerability in the MySQL Server product of Oracle MySQL, specifically within the Server: Optimizer component. The vulnerability affects supported versions ranging from 9.0.0 to 9.5.0. It is characterized as an easily exploitable flaw that allows a low privileged attacker with network access via multiple protocols to compromise the MySQL Server. Successful exploitation of this vulnerability can lead to unauthorized actions resulting in a complete denial of service (DoS) through frequent crashes or hangs of the MySQL Server.
The CVSS 3.1 Base Score assigned to this vulnerability is 6.5, indicating a medium severity level with specific impacts on availability. The CVSS vector is defined as (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). This classification suggests that while exploitation requires low complexity and privileges, it does not necessitate user interaction.
Risk to organizations includes potential downtime and operational disruptions, which can significantly affect business continuity. Given the medium severity and ease of exploitation, organizations should prioritize patching this vulnerability to avert possible service interruptions.
As of the latest updates, there are no confirmed public exploits available for this vulnerability, and it is not listed in the Known Exploited Vulnerabilities (KEV) catalog. However, organizations must remain vigilant and adopt necessary security measures to protect their MySQL Server installations.
Organizations should prioritize patching immediately. The urgency for addressing this vulnerability is underscored by its potential impact and the ease with which it can be exploited.
Vulnerability Details
The official CVE description states that this vulnerability allows low privileged attackers to compromise MySQL Server. The components affected include MySQL Server, with versions from 9.0.0 to 9.5.0 being vulnerable. The CVSS score of 6.5 indicates a medium level of severity, primarily affecting availability.
This vulnerability has been classified under CWE-400, indicating improper resource handling. Organizations are advised to review their MySQL configurations and ensure they are up-to-date with the latest security patches.
Technical Analysis
The root cause of this vulnerability lies in the MySQL Server's optimizer component, which fails to properly handle certain requests under specific conditions. This results in a crash or hang, leading to a denial of service. The attack vector is network-based, requiring low privileges for exploitation and no user interaction.
The attack complexity is low, meaning that an attacker can exploit this vulnerability without significant effort. The impacts on confidentiality and integrity are none, while the availability impact is rated as high due to the potential for system crashes.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2026-21950 is significant, particularly for organizations relying on MySQL Server for critical operations. The potential for a complete denial of service can disrupt business functions, impacting customer satisfaction and revenue.
Organizations should evaluate the blast radius of this vulnerability, considering the interconnectedness of services that might rely on the affected MySQL Server instances. Given the medium severity and lack of public exploits, immediate attention is still necessary to mitigate risks.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Oracle MySQL Server are 9.0.0 through 9.5.0. Organizations operating these versions should upgrade to the latest version to mitigate risks associated with this vulnerability.
Mitigation & Remediation
Organizations should promptly apply the necessary patches or updates provided by Oracle to remediate this vulnerability. If patching is not immediately possible, consider implementing configuration hardening measures to limit exposure and reduce the risk of exploitation.
It is also advisable to conduct a thorough security assessment through application security assessment to identify any additional vulnerabilities in your MySQL Server environment.
Detection Guidance
To detect potential exploitation attempts, organizations should monitor logs for any unusual behavior, particularly related to MySQL Server crashes or hangs. Additionally, identifying patterns of access that deviate from normal user behavior can provide insights into potential attacks.
AppSecure Threat Intelligence Insight
CVE-2026-21950 reflects a broader trend of vulnerabilities affecting database systems, where availability is often targeted. Security teams must stay vigilant and adopt a proactive approach to vulnerability management. Regular assessments and updates can significantly reduce the attack surface.
For a comprehensive understanding of penetration testing strategies, organizations should refer to the penetration testing methodology to ensure they are prepared against such vulnerabilities.
Additionally, organizations can enhance their security posture by exploring vulnerability management programs that focus on continuous improvement and risk reduction.
Finally, understanding the implications of this vulnerability can guide organizations in developing a robust security testing strategy that addresses not only this specific vulnerability but also the broader landscape of security threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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