Oracle Database Server: Improper Access Control
CVE-2026-71063 is a critical-severity improper access control vulnerability in Oracle Database Server from Oracle, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Oracle Database Server versions: 19.3 through 19.32; 21.3 through 21.23; 23.4.0 through 23.26.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Oracle Database Server you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on oracle.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Oracle | Oracle Database Server | 19.3 through 19.32; 21.3 through 21.23; 23.4.0 through 23.26.3 | Not stated |
| Oracle | Database Server | 19.3 through 19.32; 21.3 through 21.23; 23.4.0 through 23.26.3 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (oracle.com).
Official description
Vulnerability in the Portable Clusterware component of Oracle Database Server. Supported versions that are affected are 19.3-19.32, 21.3-21.23 and 23.4.0-23.26.3. Easily exploitable vulnerability allows unauthenticated attacker with access to the physical communication segment attached to the hardware where the Portable Clusterware executes to compromise Portable Clusterware. While the vulnerability is in Portable Clusterware, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in takeover of Portable Clusterware. CVSS 3.1 Base Score 9.6 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Oracle Database Server
- 7.7 High severity
- 8.1 High severity
- 8.8 High severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Access Control vulnerabilities
- 8.6 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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