CVE-2025-21540VulnerabilityPublished 21 Jan 2025Updated 3 Nov 2025

CVE-2025-21540: Oracle MySQL Server · Easily exploitable vulnerability allows low privileged attacker with network access via multiple

Affects Oracle MySQL ServerSource CVE Database V5

Not known to be exploited · CVSS 5.4 Medium · fixed in 9.1.1 : update Oracle MySQL Server when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.1.1, 8.4.4, 8.0.41

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Jan 2025
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 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade com.oracle/mysql-server to 9.1.1, 8.4.4 or 8.0.41.

Affected software

Product	Affected	Fixed in
Mavencom.oracle/mysql-server`pkg:maven/com.oracle/mysql-server`Other threats	Affected <8.0.41 <8.4.4 <9.1.1	Fixed in 8.0.41 8.4.4 9.1.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. 2. If you cannot patch yet, restrict network access to MySQL servers by implementing strict firewall rules and network segmentation to limit exposure only to trusted hosts and applications. 3. Review and enforce the principle of least privilege for MySQL user accounts, ensuring that users and applications have only the minimum necessary permissions. 4. Enable and monitor MySQL audit logs to detect unusual or unauthorized database activities, focusing on unexpected insert, update, or delete operations. 5. Use network-level controls such as VPNs or encrypted tunnels to secure MySQL traffic and reduce the risk of interception or unauthorized access. 6. Regularly update and patch all related infrastructure components to reduce the attack surface. 7. Conduct vulnerability scanning and penetration testing focused on database security to identify and remediate potential weaknesses. 8. Educate database administrators and security teams about this vulnerability and the importance of rapid response to newly disclosed threats.

Description

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Security: Privileges). Supported versions that are affected are 8.0.40 and prior, 8.4.3 and prior and 9.1.0 and prior. 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 update, insert or delete access to some of MySQL Server accessible data as well as unauthorized read access to a subset of MySQL Server accessible data. CVSS 3.1 Base Score 5.4 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N).

Impact

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of data stored in MySQL databases. Unauthorized read access could lead to data leakage of sensitive information, while unauthorized write access could result in data corruption, loss of data integrity, or manipulation of critical business data. Industries such as finance, healthcare, telecommunications, and government agencies that rely heavily on MySQL for transactional and operational databases could face regulatory compliance issues, reputational damage, and operational disruptions. Since the vulnerability can be exploited remotely with low privileges and no user interaction, attackers could leverage this flaw to escalate privileges or move laterally within networks. The absence of availability impact reduces the risk of denial-of-service, but the data integrity and confidentiality concerns remain significant. The medium severity score indicates that while the threat is not critical, it requires timely mitigation to prevent potential exploitation, especially in environments with exposed MySQL servers or weak network segmentation.

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 01:14 UTC

WeaknessesCWE-863

Technical details

References

Community reviews

Related threats