Amazon Linux 2 : docker, --advisory ALAS2ECS-2026-131 (ALASECS-2026-131)

high Nessus Plugin ID 325565

Synopsis

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

Description

The version of docker installed on the remote host is prior to 25.0.16-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2ECS-2026-131 advisory.

(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, .) to execute repeatedly on the same input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before building the certificate chain, this overhead occurred even for untrusted certificates. (CVE-2026-27145)

Moby is an open source container framework. In versions prior to 29.5.1 and in moby/moby v2 prior to v2.0.0-beta.14, when a compressed archive is uploaded to a container via `PUT /containers/{id}/archive` or piped through `docker cp -`, the daemon resolves decompression binaries (such as `xz` or `unpigz`) from the container's filesystem rather than the host's due to incorrect ordering of operations. A malicious container image containing a trojanized decompression binary can achieve arbitrary code execution with full daemon privileges, including host root UID and unrestricted capabilities, when a user uploads a compressed (xz or gzip) archive into that container. This issue is fixed in Docker Engine 29.5.1 and moby/moby v2.0.0-beta.14. Workarounds include only running containers from trusted images, using authorization plugins to restrict access to the `PUT /containers/{id}/archive` endpoint, and avoiding piping compressed archives into containers created from untrusted images (CVE-2026-41567)

Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU. (CVE-2026-42504)

When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.
(CVE-2026-42507)

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 docker' or or 'yum update --advisory ALAS2ECS-2026-131' to update your system.

Plugin Details

Severity: High

ID: 325565

File Name: al2_ALASECS-2026-131.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 7/8/2026

Updated: 7/8/2026

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

Percentile: 94.15

CVSS v2

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.5

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

CVSS Score Source: CVE-2026-27145

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS Score Source: CVE-2026-41567

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:docker, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:docker-debuginfo

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/8/2026

Vulnerability Publication Date: 5/18/2026

Reference Information

CVE: CVE-2026-27145, CVE-2026-41567, CVE-2026-42504, CVE-2026-42507

IAVB: 2026-B-0146

Detections

Analytics