CVE-2026-16239
Description
A flaw was found in PostgreSQL. This vulnerability, caused by type confusion in the 'portal'/cursor lifecycle, allows a user to execute arbitrary code as the operating system user running the database. This can occur by re-creating a cursor or other portal with different types. Successful exploitation could lead to a complete compromise of the database system.
Statement
This is an Important vulnerability in PostgreSQL. A type confusion flaw in the cursor lifecycle allows a low-privileged authenticated database user to execute arbitrary code as the operating system user running the database. This can lead to a complete compromise of the database system, making it a significant risk in typical Red Hat deployments where PostgreSQL instances are exposed to authenticated users.
Mitigation
To mitigate this vulnerability, restrict direct database access strictly to trusted roles and minimize multi-tenant database scenarios where untrusted users can execute arbitrary SQL. Monitor database audit logs for anomalous or high-frequency cursor lifecycle activities involving unexpected CLOSE and DECLARE operations.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
When a memory buffer is accessed using the wrong type, it could read or write memory out of the bounds of the buffer, if the allocated buffer is smaller than the type that the code is attempting to access, leading to a crash and possibly code execution.
Frequently Asked Questions
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