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RHEL 9 : nginx (RHSA-2026:66542)

critical Nessus Plugin ID 344771

Synopsis

The remote Red Hat host is missing a security update for nginx.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:66542 advisory.

 nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

 Security Fix(es):

 * nginx: NGINX: Arbitrary code execution via crafted HTTP requests (CVE-2026-42533)

 For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL nginx package based on the guidance in RHSA-2026:66542.

See Also

https://access.redhat.com/errata/RHSA-2026:66542

https://access.redhat.com/security/updates/classification/#important

https://bugzilla.redhat.com/show_bug.cgi?id=2500967

http://www.nessus.org/u?c2fc83b9

Plugin Details

Severity: Critical

ID: 344771

File Name: redhat-RHSA-2026-66542.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/11/2026

Updated: 9/11/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.36

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 6

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

CVSS Score Source: CVE-2026-42533

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.3

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:P/RL:O/RC:C

CVSS v4

Risk Factor: Critical

Base Score: 9.2

Threat Score: 8.2

Threat Vector: CVSS:4.0/E:P

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

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:9, cpe:/o:redhat:rhel_eus:9.8, p-cpe:/a:redhat:enterprise_linux:nginx-all-modules, p-cpe:/a:redhat:enterprise_linux:nginx-core, p-cpe:/a:redhat:enterprise_linux:nginx-filesystem, p-cpe:/a:redhat:enterprise_linux:nginx-mod-devel, p-cpe:/a:redhat:enterprise_linux:nginx-mod-http-image-filter, p-cpe:/a:redhat:enterprise_linux:nginx-mod-http-perl, p-cpe:/a:redhat:enterprise_linux:nginx-mod-http-xslt-filter, p-cpe:/a:redhat:enterprise_linux:nginx-mod-mail, p-cpe:/a:redhat:enterprise_linux:nginx-mod-stream, p-cpe:/a:redhat:enterprise_linux:nginx

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/11/2026

Vulnerability Publication Date: 7/15/2026

Reference Information

CVE: CVE-2026-42533

CWE: 131

RHSA: 2026:66542