CentOS Linux 8 [TuxCare] Security Update: rsync / rsync-daemon Multiple Vulnerabilities (CENTOS-STREAM8:CLSA-2026:1793724443)

critical Nessus Plugin ID 375528

Synopsis

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

Description

The CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS-STREAM8:CLSA-2026:1793724443 advisory.

- Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false. (CVE-2026-29518)

- rsync before 3.5.0 contains a path confinement bypass vulnerability that allows remote clients to escape the intended inner-module root confinement by constructing paths that resolve outside the chroot boundary when the module root contains a /./ boundary marker. Attackers can exploit improper handling of the /./ notation or forge delta-basis transfers referencing xname paths that cross the /./ boundary to gain unauthorized read or write access to files outside the module's subtree. (CVE-2026-53793)

- rsync before 3.5.0 contains an arbitrary file read vulnerability that allows attackers to read files accessible to the rsync daemon process by exploiting symlink following in input configuration file handling including --files-from, --password-file, and filter merge files. Attackers can place a symlink at a predictable --files-from or --password-file path, or supply a --files-from path that escapes the daemon module root, to read arbitrary files accessible to the rsync process. (CVE-2026-53802)

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 CENTOS-STREAM8:CLSA-2026:1793724443.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1793724443

http://www.nessus.org/u?502f36c0

Plugin Details

Severity: Critical

ID: 375528

File Name: tuxcare_centos_8_CLSA-2026-1793724443.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 11/3/2026

Updated: 11/3/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 94.26

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.3

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

CVSS Score Source: CVE-2026-53793

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

CVSS Score Source: CVE-2026-29518

CVSS v4

Risk Factor: Critical

Base Score: 9.1

Threat Score: 6.9

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:N/SC:N/SI:N/SA:N

Vulnerability Information

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/3/2026

Vulnerability Publication Date: 5/20/2026

Reference Information

CVE: CVE-2026-29518, CVE-2026-53793, CVE-2026-53802

CLSA: 2026:1793724443