Amazon Linux 2 : nginx, --advisory ALAS2NGINX1-2026-014 (ALASNGINX1-2026-014)

critical Nessus Plugin ID 325580

Synopsis

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

Description

The version of nginx installed on the remote host is prior to 1.30.3-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2NGINX1-2026-014 advisory.

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request.
This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart.
Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
(CVE-2026-42055)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset utf-8; and a charset directive (for example, charset koi8-r;) configured, remote, unauthenticated attackers can send requests (in conjunction with conditions beyond their control) to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
(CVE-2026-48142)

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 nginx' or or 'yum update --advisory ALAS2NGINX1-2026-014' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2NGINX1-2026-014.html

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

https://explore.alas.aws.amazon.com/CVE-2026-42055.html

https://explore.alas.aws.amazon.com/CVE-2026-48142.html

Plugin Details

Severity: Critical

ID: 325580

File Name: al2_ALASNGINX1-2026-014.nasl

Version: 1.1

Type: Local

Agent: unix

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: High

Score: 7.7

Percentile: 99.06

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-42055

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

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

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

CVSS v4

Risk Factor: Critical

Base Score: 9.2

Threat Score: 7.2

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:nginx, p-cpe:/a:amazon:linux:nginx-core, p-cpe:/a:amazon:linux:nginx-mod-mail, p-cpe:/a:amazon:linux:nginx-mod-http-perl, p-cpe:/a:amazon:linux:nginx-mod-stream, p-cpe:/a:amazon:linux:nginx-mod-http-image-filter, p-cpe:/a:amazon:linux:nginx-all-modules, p-cpe:/a:amazon:linux:nginx-mod-http-xslt-filter, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:nginx-debuginfo, p-cpe:/a:amazon:linux:nginx-filesystem, p-cpe:/a:amazon:linux:nginx-mod-devel, p-cpe:/a:amazon:linux:nginx-mod-http-geoip

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: 6/17/2026

Reference Information

CVE: CVE-2026-42055, CVE-2026-48142

IAVA: 2026-A-0601