Amazon Linux 2 : containerd, --advisory ALAS2DOCKER-2026-120 (ALASDOCKER-2026-120)

high Nessus Plugin ID 316919

Synopsis

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

Description

The version of containerd installed on the remote host is prior to 2.1.7-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2DOCKER-2026-120 advisory.

When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash. (CVE-2026-33811)

When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a value of 0. (CVE-2026-33814)

Well-crafted inputs reaching ParseAddress, ParseAddressList, and ParseDate were able to trigger excessive CPU exhaustion and memory allocations. (CVE-2026-39820)

CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a <meta> tag's <content> attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the <content> attribute, the escaper would fail to similarly escape it, leading to XSS. (CVE-2026-39823)

ReverseProxy can forward queries containing parameters not visible to Rewrite functions. When used with a Rewrite function, or a Director function which parses query parameters, ReverseProxy sanitizes the forwarded request to remove query parameters which are not parsed by url.ParseQuery. ReverseProxy does not take ParseQuery's limit on the total number of query parameters (controlled by GODEBUG=urlmaxqueryparams=N) into account. This can permit ReverseProxy to forward a request containing a query parameter that is not visible to the Rewrite function. For example, the query a1=x&a2=x&...&a10000=x&hidden=y can forward the parameter hidden=y while hiding it from the proxy's Rewrite function. (CVE-2026-39825)

If a trusted template author were to write a <script> tag containing an empty 'type' attribute or a 'type' attribute with an ASCII whitespace, the execution of the template would incorrectly escape any data passed into the <script> block. (CVE-2026-39826)

Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322. (CVE-2026-42499)

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 containerd' or or 'yum update --advisory ALAS2DOCKER-2026-120' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2DOCKER-2026-120.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-33811.html

https://explore.alas.aws.amazon.com/CVE-2026-33814.html

https://explore.alas.aws.amazon.com/CVE-2026-39820.html

https://explore.alas.aws.amazon.com/CVE-2026-39823.html

https://explore.alas.aws.amazon.com/CVE-2026-39825.html

https://explore.alas.aws.amazon.com/CVE-2026-39826.html

https://explore.alas.aws.amazon.com/CVE-2026-42499.html

Plugin Details

Severity: High

ID: 316919

File Name: al2_ALASDOCKER-2026-120.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: 4.4

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-2026-39820

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:containerd, p-cpe:/a:amazon:linux:containerd-debuginfo, p-cpe:/a:amazon:linux:containerd-stress

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

Exploit Ease: No known exploits are available

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 5/7/2026

Reference Information

CVE: CVE-2026-33811, CVE-2026-33814, CVE-2026-39820, CVE-2026-39823, CVE-2026-39825, CVE-2026-39826, CVE-2026-42499

IAVB: 2026-B-0120