CVE-2026-116306
Description
A flaw was found in PostgreSQL. An authenticated user with database object creation privileges can trigger a type confusion issue during composite-value field assignments by altering composite types between operations. Successful exploitation allows an attacker to execute arbitrary code on the host system with the privileges of the operating system account running the database service.
Statement
Red Hat Product Security rates this vulnerability as an Important severity issue because authenticated clients granted schema modification rights can escalate access to execute arbitrary commands under the operating system account managing PostgreSQL, resulting in a full compromise of database integrity and confidentiality. In standard Red Hat Enterprise Linux deployments, the database daemon operates under a dedicated, unprivileged system user (postgres), which confines the blast radius to database files and local service assets rather than full root access. Triggering the flaw requires the ability to construct and manipulate composite types within an active session, preventing unauthenticated external actors or read-only accounts from exploiting the issue.
Mitigation
Restrict network access to the PostgreSQL service to trusted hosts and revoke schema creation permissions from untrusted database accounts.
1. Restrict PostgreSQL network exposure using firewalld to only authorized subnets:
firewall-cmd --permanent --remove-service=postgresql
firewall-cmd --permanent --zone=trusted --add-source=<trusted_ip_or_subnet>
firewall-cmd --permanent --zone=trusted --add-service=postgresql
firewall-cmd --reload
2. Restrict object creation privileges within the database:
REVOKE CREATE ON SCHEMA <schema_name> FROM <username>;
Caveats:
Restricting network connectivity mitigates untrusted external exposure but does not prevent exploitation from authorized systems or accounts. Revoking schema creation privileges may break application workflows that require creating custom or temporary data types.
Warning: Executing `firewall-cmd --reload` modifies active firewall rules and may temporarily interrupt active database connections.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
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)
Other
Technical Impact: Varies by Context
When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties.
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
If a memory buffer is accessed using an incompatible type, and the allocated buffer is smaller than the type that the code is attempting to access, then an attacker could read or write memory outside the bounds of the buffer, leading to a crash or possibly code execution.
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