AlmaLinux 9.2 [TuxCare] Security Update: libssh / libssh-config / libssh-devel Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1786446507)

medium Nessus Plugin ID 362095

Synopsis

The AlmaLinux host is missing one or more security updates.

Description

The AlmaLinux 9.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1786446507 advisory.

- A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service. (CVE-2026-59843)

- A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service. (CVE-2026-59845)

- A flaw was found in libssh. A malicious SFTP server can send responses for unknown request IDs that libssh clients keep queued indefinitely, causing unbounded memory growth and client-side denial of service.
(CVE-2026-59848)

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 ALMALINUX9.2:CLSA-2026:1786446507.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1786446507

http://www.nessus.org/u?e9bb52dd

Plugin Details

Severity: Medium

ID: 362095

File Name: tuxcare_alma_linux_9.2_CLSA-2026-1786446507.nasl

Version: 1.1

Type: Local

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 51.06

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-59845

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

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

Vulnerability Information

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/11/2026

Vulnerability Publication Date: 7/21/2026

Reference Information

CVE: CVE-2026-59843, CVE-2026-59845, CVE-2026-59848

CLSA: 2026:1786446507