TencentOS Server 4: pcs (TSSA-2026:1351)

high Nessus Plugin ID 376225

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-2026:1351 advisory.

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

CVE-2026-49855:
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.

CVE-2026-49853:
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, SimpleAsyncHTTPClient shallow-copied redirected requests and removed only the Host header, leaving Authorization, auth_username, auth_password, and auth_mode in place when a redirect changed scheme, host, or port. This issue is fixed in version 6.5.6.

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.

Plugin Details

Severity: High

ID: 376225

File Name: tencentos_TSSA_2026_1351.nasl

Version: 1.1

Type: Local

Family: Tencent Local Security Checks

Published: 11/5/2026

Updated: 11/5/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 51.2

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-49853

CVSS v3

Risk Factor: High

Base Score: 7.7

Temporal Score: 6.7

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

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

Vulnerability Information

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

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/3/2026

Vulnerability Publication Date: 6/15/2026

Reference Information

CVE: CVE-2026-49853, CVE-2026-49855

Detections

Analytics