RHEL 8 : libpq (RHSA-2026:27738)

high Nessus Plugin ID 321933

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Synopsis

The remote Red Hat host is missing one or more security updates for libpq.

Description

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:27738 advisory.

The libpq package provides the PostgreSQL client library, which allows client programs to connect to PostgreSQL servers.

Security Fix(es):

* postgresql: PostgreSQL: Operating system account hijack via symlink following in pg_basebackup and pg_rewind (CVE-2026-6475)

* postgresql: PostgreSQL libpq: Buffer overflow allows server superuser to overwrite client stack memory (CVE-2026-6477)

* postgresql: PostgreSQL: Credential recovery via covert timing channel in MD5 password comparison (CVE-2026-6478)

* postgresql: integer overflow can cause an undersized allocation and an out-of-bounds write (CVE-2026-6473)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL libpq package based on the guidance in RHSA-2026:27738.

Plugin Details

Severity: High

ID: 321933

File Name: redhat-RHSA-2026-27738.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 6/22/2026

Updated: 7/3/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.92

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-6477

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2026-6475

Vulnerability Information

CPE: cpe:/o:redhat:rhel_eus:8.10, p-cpe:/a:redhat:enterprise_linux:libpq, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:libpq-devel

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 6/22/2026

Vulnerability Publication Date: 5/14/2026

Reference Information

CVE: CVE-2026-6473, CVE-2026-6475, CVE-2026-6477, CVE-2026-6478

CWE: 120, 190, 385, 59

RHSA: 2026:27738

Detections

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