CentOS Linux 7 [TuxCare] Security Update: cups / cups-client / cups-devel / cups-filesystem / cups-ipptool / etc Multiple Vulnerabilities (CENTOS7:CLSA-2026:1794008159)

medium Nessus Plugin ID 378948

Synopsis

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

Description

The CentOS Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS7:CLSA-2026:1794008159 advisory.

- OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/<connection-number>.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20. (CVE-2026-55480)

- OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_banner() in scheduler/ipp.c uses the attacker-controlled IPP attributes-natural-language value as a directory component beneath DataDir/banners when processing a job-sheets banner. The job-sheets value must first match a registered banner basename, and the traversed path must contain a matching reachable basename; selecting an arbitrary target as demonstrated additionally requires pre-positioned path state such as a symlink with that basename. Subject to the scheduler's filesystem and sandbox access, path separators in the language value can escape the intended banner directory, make the root scheduler open the reachable file, and copy its bytes into a job-sheet spool object that a configured backend can deliver to an attacker-observable endpoint. This issue is fixed in version 2.4.20. (CVE-2026-61702)

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 based on the guidance in TuxCare advisory CENTOS7:CLSA-2026:1794008159.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1794008159

http://www.nessus.org/u?8e862446

Plugin Details

Severity: Medium

ID: 378948

File Name: tuxcare_centos_7_CLSA-2026-1794008159.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 11/11/2026

Updated: 11/11/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.54

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.1

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

CVSS Score Source: CVE-2026-55480

CVSS v3

Risk Factor: Medium

Base Score: 5.7

Temporal Score: 5.1

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

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

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: 11/6/2026

Vulnerability Publication Date: 10/15/2026

Reference Information

CVE: CVE-2026-55480, CVE-2026-61702

CLSA: 2026:1794008159