ALAS2-2026-3820


Amazon Linux 2 Security Advisory: ALAS2-2026-3820
Advisory Released Date: 2026-07-20
Advisory Updated Date: 2026-07-20
Severity: Important

Issue Overview:

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

This vulnerability is due to improper boundary checks for content in PE files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains PE 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-2026-20213)

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

This vulnerability is due to improper boundary checks for content in FSG files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains portable executable content compressed with FSG 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-2026-20214)

A vulnerability in the 7z file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

This vulnerability is due to improper boundary checks for content in 7z files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains 7z 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-2026-20215)

A vulnerability in the InstallShield file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device.

This vulnerability is due to improper handling of temporary resources during file scanning. An attacker could exploit this vulnerability by submitting a crafted InstallShield file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process and temporarily consume available system resources, resulting in a DoS condition on the affected software. (CVE-2026-20216)

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, resulting from 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 out-of-bounds buffer write. 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-2026-20217)

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

This vulnerability is due to improper boundary checks for content in ALZ files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains ALZ 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-2026-20243)


Affected Packages:

clamav1.4


Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.


Issue Correction:
Run yum update clamav1.4 or yum update --advisory ALAS2-2026-3820 to update your system.

New Packages:
aarch64:
    clamav1.4-1.4.5-1.amzn2.0.1.aarch64
    clamav1.4-lib-1.4.5-1.amzn2.0.1.aarch64
    clamav1.4-devel-1.4.5-1.amzn2.0.1.aarch64
    clamav1.4-freshclam-1.4.5-1.amzn2.0.1.aarch64
    clamd1.4-1.4.5-1.amzn2.0.1.aarch64
    clamav1.4-milter-1.4.5-1.amzn2.0.1.aarch64
    clamav1.4-debuginfo-1.4.5-1.amzn2.0.1.aarch64

noarch:
    clamav1.4-filesystem-1.4.5-1.amzn2.0.1.noarch
    clamav1.4-data-1.4.5-1.amzn2.0.1.noarch
    clamav1.4-doc-1.4.5-1.amzn2.0.1.noarch

src:
    clamav1.4-1.4.5-1.amzn2.0.1.src

x86_64:
    clamav1.4-1.4.5-1.amzn2.0.1.x86_64
    clamav1.4-lib-1.4.5-1.amzn2.0.1.x86_64
    clamav1.4-devel-1.4.5-1.amzn2.0.1.x86_64
    clamav1.4-freshclam-1.4.5-1.amzn2.0.1.x86_64
    clamd1.4-1.4.5-1.amzn2.0.1.x86_64
    clamav1.4-milter-1.4.5-1.amzn2.0.1.x86_64
    clamav1.4-debuginfo-1.4.5-1.amzn2.0.1.x86_64