Oracle Linux 8 : dnsmasq (ELSA-2026-20589)

high Nessus Plugin ID 316920

Synopsis

The remote Oracle Linux host is missing one or more security updates.

Description

The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-20589 advisory.

- Prevent overflow in extract_name function (CVE-2026-2291)
- Prevent DoS in DNSSEC validation (CVE-2026-4890)
- Prevent out-of-bounds read in DNSSEC validation (CVE-2026-4891)
- Prevent out-of-bounds write in DHCPv6 server (CVE-2026-4892)

Tenable has extracted the preceding description block directly from the Oracle 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 affected dnsmasq and / or dnsmasq-utils packages.

See Also

https://linux.oracle.com/errata/ELSA-2026-20589.html

Plugin Details

Severity: High

ID: 316920

File Name: oraclelinux_ELSA-2026-20589.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 5/27/2026

Updated: 5/27/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

CVSS v2

Risk Factor: High

Base Score: 8.3

Temporal Score: 6.1

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

CVSS Score Source: CVE-2026-4892

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.3

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

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

Vulnerability Information

CPE: cpe:/o:oracle:linux:8, p-cpe:/a:oracle:linux:dnsmasq, p-cpe:/a:oracle:linux:dnsmasq-utils

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

Exploit Ease: No known exploits are available

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 5/11/2026

Reference Information

CVE: CVE-2026-2291, CVE-2026-4890, CVE-2026-4891, CVE-2026-4892, CVE-2026-4893

IAVA: 2026-A-0450