CentOS Linux 8.5 [TuxCare] Security Update: mod_http2 Multiple Vulnerabilities (CENTOS8.5:CLSA-2026:1794571312)

critical Nessus Plugin ID 380757

Synopsis

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

Description

The CentOS Linux 8.5 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare CENTOS8.5:CLSA-2026:1794571312 advisory.

- In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2.
Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to on. (CVE-2025-49630)

- Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern matches some portion of the user-supplied request-target (URL) data and is then re-inserted into the proxied request-target using variable substitution. For example, something like: RewriteEngine on RewriteRule ^/here/(.*) http://example.com:8080/elsewhere?$1; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server. (CVE-2023-25690)

- HTTP/2 incoming headers exceeding the limit are temporarily buffered in nghttp2 in order to generate an informative HTTP 413 response. If a client does not stop sending headers, this leads to memory exhaustion.
(CVE-2024-27316)

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

Solution

Update the affected mod_http2 package based on the guidance in TuxCare advisory CENTOS8.5:CLSA-2026:1794571312.

Plugin Details

Severity: Critical

ID: 380757

File Name: tuxcare_centos_8.5_CLSA-2026-1794571312.nasl

Version: 1.1

Type: Local

Agent: unix

Family: CentOS Local Security Checks

Published: 11/13/2026

Updated: 11/13/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.26

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2023-25690

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/13/2026

Vulnerability Publication Date: 3/7/2023

Reference Information

CVE: CVE-2023-25690, CVE-2024-27316, CVE-2025-49630

CLSA: 2026:1794571312

Detections

Analytics