Detections
Analytics

TencentOS Server 4: nginx (TSSA-2026:0398)

critical Nessus Plugin ID 319760

Synopsis

The remote TencentOS Server 4 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0398 advisory.

 Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

 CVE-2026-9256:
 NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl- Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. 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. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

 CVE-2026-40701:
 NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_modulemodule when the ssl_verify_clientdirective is set to on or optional, and the ssl_ocspdirective is set to on or the leafparameters are configured with a resolver. With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.



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

Tenable has extracted the preceding description block directly from the Tencent Linux 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

Update the affected packages.

See Also

https://mirrors.tencent.com/tlinux/errata/tssa-20260398.xml

Plugin Details

Severity: Critical

ID: 319760

File Name: tencentos_TSSA_2026_0398.nasl

Version: 1.1

Type: Local

Published: 6/8/2026

Updated: 6/8/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.1

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

CVSS Score Source: CVE-2026-40701

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 Score Source: CVE-2026-9256

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:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-9256

Vulnerability Information

CPE: p-cpe:/a:tencent:tencentos_server:nginx, cpe:/o:tencent:tencentos_server:4

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/4/2026

Vulnerability Publication Date: 5/13/2026

Reference Information

CVE: CVE-2026-40701, CVE-2026-9256

IAVA: 2026-A-0515