RockyLinux 10 : libssh (RLSA-2026:55855)

high Nessus Plugin ID 337638

Synopsis

The remote RockyLinux host is missing one or more security updates.

Description

The remote RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:55855 advisory.

* libssh: libssh: information disclosure via short GSSAPI Curve25519 public key (CVE-2026-59842)

* libssh: libssh: denial of service via zero advertised channel packet size (CVE-2026-59843)

* libssh: libssh: denial of service via oversized SFTP read length (CVE-2026-59844)

* libssh: libssh: denial of service via unchecked ProxyCommand fork() failure (CVE-2026-59845)

* libssh: libssh: information disclosure via ProxyCommand %r username expansion (CVE-2026-59846)

* libssh: libssh: integrity downgrade via OpenSSL AES-GCM tag verification (CVE-2026-59847)

* libssh: libssh: denial of service via SFTP responses with unknown request IDs (CVE-2026-59848)

* libssh: libssh: denial of service via automatic certificate authentication loop (CVE-2026-59849)

* libssh: libssh: use-after-free via data callbacks on closed channels (CVE-2026-59850)

* libssh: libssh: authentication bypass via missing GSSAPI principal check (CVE-2026-59851)

* libssh: libssh: stack buffer overflow in SFTP server longname construction (CVE-2026-15370)

Tenable has extracted the preceding description block directly from the RockyLinux 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://bugzilla.redhat.com/show_bug.cgi?id=2498168

https://bugzilla.redhat.com/show_bug.cgi?id=2498176

https://bugzilla.redhat.com/show_bug.cgi?id=2498177

https://bugzilla.redhat.com/show_bug.cgi?id=2498178

https://bugzilla.redhat.com/show_bug.cgi?id=2498179

https://bugzilla.redhat.com/show_bug.cgi?id=2498180

https://bugzilla.redhat.com/show_bug.cgi?id=2498181

https://bugzilla.redhat.com/show_bug.cgi?id=2498182

https://bugzilla.redhat.com/show_bug.cgi?id=2498183

https://bugzilla.redhat.com/show_bug.cgi?id=2498184

https://bugzilla.redhat.com/show_bug.cgi?id=2499049

https://errata.rockylinux.org/RLSA-2026:55855

Plugin Details

Severity: High

ID: 337638

File Name: rocky_linux_RLSA-2026-55855.nasl

Version: 1.1

Type: Local

Published: 8/18/2026

Updated: 8/18/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.13

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-59847

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:rocky:linux:10, p-cpe:/a:rocky:linux:libssh-config, p-cpe:/a:rocky:linux:libssh-debuginfo, p-cpe:/a:rocky:linux:libssh-debugsource, p-cpe:/a:rocky:linux:libssh-devel, p-cpe:/a:rocky:linux:libssh

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/RockyLinux/release, Host/RockyLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/18/2026

Vulnerability Publication Date: 7/21/2026

Reference Information

CVE: CVE-2026-15370, CVE-2026-59842, CVE-2026-59843, CVE-2026-59844, CVE-2026-59845, CVE-2026-59846, CVE-2026-59847, CVE-2026-59848, CVE-2026-59849, CVE-2026-59850, CVE-2026-59851