Amazon Linux 2 : clamav1.4, --advisory ALAS2-2026-3894 (ALAS-2026-3894)

high Nessus Plugin ID 341843

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of clamav1.4 installed on the remote host is prior to 1.4.6-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3894 advisory.

A vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device.

This vulnerability is due to improper boundary checks for content in PESpin files during scanning, which may result in an integer overflow. An attacker could exploit this vulnerability by submitting a crafted file that contains PESpin content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software. (CVE-2026-20339)

A vulnerability in the GPT file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device.

This vulnerability is due to improper handling of an endian conversion operation, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted GPT file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.
(CVE-2026-20345)

A vulnerability in the PDF file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device.

This vulnerability is due to improper boundary checks for content in PDF files during scanning, which may result in an out-of-bounds buffer read. An attacker could exploit this vulnerability by submitting a crafted PDF file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software. (CVE-2026-20346)

A vulnerability in the Mach-O file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device.

This vulnerability is due to improper boundary checks for content in Mach-O files during scanning, which may result in an out-of-bounds buffer read. An attacker could exploit this vulnerability by submitting a crafted Mach-O file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software. (CVE-2026-20347)

A vulnerability in the XAR file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device.

This vulnerability is due to improper boundary checks for content in XAR files during scanning. An attacker could exploit this vulnerability by submitting a crafted file that contains XAR content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software. (CVE-2026-20348)

Tenable has extracted the preceding description block directly from the tested product 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

Run 'yum update clamav1.4' or or 'yum update --advisory ALAS2-2026-3894' to update your system.

Plugin Details

Severity: High

ID: 341843

File Name: al2_ALAS-2026-3894.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/31/2026

Updated: 8/31/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 96.22

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-20348

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:clamav1.4-data, p-cpe:/a:amazon:linux:clamav1.4-debuginfo, p-cpe:/a:amazon:linux:clamav1.4-devel, p-cpe:/a:amazon:linux:clamav1.4-doc, p-cpe:/a:amazon:linux:clamav1.4-filesystem, p-cpe:/a:amazon:linux:clamav1.4-freshclam, p-cpe:/a:amazon:linux:clamav1.4-lib, p-cpe:/a:amazon:linux:clamav1.4-milter, p-cpe:/a:amazon:linux:clamav1.4, p-cpe:/a:amazon:linux:clamd1.4

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/31/2026

Vulnerability Publication Date: 8/7/2026

Reference Information

CVE: CVE-2026-20339, CVE-2026-20345, CVE-2026-20346, CVE-2026-20347, CVE-2026-20348

IAVB: 2026-B-0225

Detections

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