RHEL 9 : kernel-rt (RHSA-2026:71606)

medium Nessus Plugin ID 349740

Synopsis

The remote Red Hat host is missing one or more security updates for kernel-rt.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:71606 advisory.

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

* kernel: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg (CVE-2025-39964)

* kernel: netfilter: ebtables SNAT target writes to shared memory pages during ARP hardware address rewrite (CVE-2026-53266)

* kernel: Linux kernel: PPPoE memory corruption via stale pointer (CVE-2026-68121)

* kernel: sctp: prevent peer transport count overflow (CVE-2026-74469)

* kernel: xfrm: ah6: validate routing header segments_left (CVE-2026-80844)

* kernel: net: tun: bound receive headroom (CVE-2026-81000)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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 RHEL kernel-rt package based on the guidance in RHSA-2026:71606.

Plugin Details

Severity: Medium

ID: 349740

File Name: redhat-RHSA-2026-71606.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 9/24/2026

Updated: 9/24/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.3

Percentile: 99.82

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.8

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

CVSS Score Source: CVE-2025-39964

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5.1

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

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

Vulnerability Information

CPE: cpe:/o:redhat:rhel_e4s:9.2, p-cpe:/a:redhat:enterprise_linux:kernel-rt-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/24/2026

Vulnerability Publication Date: 10/10/2025

CISA Known Exploited Vulnerability Due Dates: 9/21/2026

Reference Information

CVE: CVE-2025-39964, CVE-2026-53266, CVE-2026-68121, CVE-2026-74469, CVE-2026-80844, CVE-2026-81000

CWE: 366, 787, 805, 825

RHSA: 2026:71606

Detections

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