AlmaLinux 9.2 [TuxCare] Security Update: nginx / nginx-all-modules / nginx-core / nginx-filesystem / etc (ALMALINUX9.2:CLSA-2026:1783696553)

critical Nessus Plugin ID 352111

Synopsis

The AlmaLinux host is missing one or more security updates.

Description

The AlmaLinux 9.2 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1783696553 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)

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 ALMALINUX9.2:CLSA-2026:1783696553.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1783696553

http://www.nessus.org/u?4f75f6c4

Plugin Details

Severity: Critical

ID: 352111

File Name: tuxcare_alma_linux_9.2_CLSA-2026-1783696553.nasl

Version: 1.1

Type: Local

Published: 9/30/2026

Updated: 9/30/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.18

Vendor

Vendor Severity: Low

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

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/10/2026

Vulnerability Publication Date: 6/17/2026

Reference Information

CVE: CVE-2026-42055

CLSA: 2026:1783696553