CentOS Linux 8.4 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-filesystem / etc (CENTOS8.4:CLSA-2026:1784800112)

critical Nessus Plugin ID 359714

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 8.4 host has packages installed that are affected by a vulnerability as referenced in the TuxCare CENTOS8.4:CLSA-2026:1784800112 advisory.

- A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression references the map's regex capture variables before referencing the map output variable.
Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap 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. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
(CVE-2026-42533)

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 affected packages based on the guidance in TuxCare advisory CENTOS8.4:CLSA-2026:1784800112.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1784800112

http://www.nessus.org/u?50bcbca7

Plugin Details

Severity: Critical

ID: 359714

File Name: tuxcare_centos_8.4_CLSA-2026-1784800112.nasl

Version: 1.2

Type: Local

Agent: unix

Published: 10/1/2026

Updated: 10/2/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.35

Vendor

Vendor Severity: Low

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 6.3

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: 7.5

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:F/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

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/23/2026

Vulnerability Publication Date: 7/15/2026

Exploitable With

Core Impact

Reference Information

CVE: CVE-2026-42533

CLSA: 2026:1784800112