CVE-2026-21952: Oracle MySQL Server · Uncontrolled Resource Consumption
Affects Oracle MySQL ServerSource CVE Database V5
Not known to be exploited · CVSS 4.9 Medium.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Oracle CorporationMySQL Server | Affected
| Fixed in– |
AI-suggested
1. Restrict network access to MySQL Server instances to trusted hosts and networks only, using firewalls and network segmentation to limit exposure. 2. Enforce strict access controls and minimize the number of users with high privileges to reduce the attack surface. 3. Monitor MySQL Server logs and network traffic for unusual activity or repeated crashes that may indicate exploitation attempts. 4. Implement robust authentication and authorization mechanisms to prevent unauthorized privilege escalation. 5. Prepare incident response plans to quickly recover from potential DoS conditions, including database restarts and failover procedures. 6. Stay alert for official patches or updates from Oracle and apply them promptly once available. 7. Consider deploying MySQL Server in high-availability configurations to mitigate downtime impact. 8. Conduct regular security audits and vulnerability assessments focusing on database security posture. 9. If possible, use application-layer filtering or proxies to validate and sanitize incoming queries to the database server.
Description
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Parser). Supported versions that are affected are 9.0.0-9.5.0. 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).