RHEL 9 : kernel-rt (RHSA-2026:19875)

high Nessus Plugin ID 316001

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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-2026:19875 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: proc: fix UAF in proc_get_inode() (CVE-2025-21999)

* kernel: Linux kernel (qla2xxx): Double free vulnerability leads to denial of service and potential privilege escalation. (CVE-2025-71238)

* kernel: Linux kernel: Denial of service and memory corruption in RDMA umad (CVE-2026-23243)

* kernel: Linux kernel KVM: Privilege escalation or denial of service due to improper shadow page table entry handling (CVE-2026-23401)

* kernel: can: raw: fix ro->uniq use-after-free in raw_rcv() (CVE-2026-31532)

* kernel: Fragnesia is a variant of Dirty Frag vulnerability in the ESP/XFRM leading to Local Privilege Escalation (LPE) vulnerability in the Linux kernel (CVE-2026-46300)

* kernel: Read root-owned files as an unprivileged user (CVE-2026-46333)

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-2026:19875.

Plugin Details

Severity: High

ID: 316001

File Name: redhat-RHSA-2026-19875.nasl

Version: 1.4

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 5/21/2026

Updated: 6/16/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.9

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

CVSS Score Source: CVE-2026-46300

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

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

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

Vulnerability Information

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

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: 5/20/2026

Vulnerability Publication Date: 4/3/2025

Exploitable With

Core Impact

Reference Information

CVE: CVE-2025-21999, CVE-2025-71238, CVE-2026-23243, CVE-2026-23401, CVE-2026-31532, CVE-2026-46300, CVE-2026-46333

CWE: 123, 131, 269, 366, 416, 672

RHSA: 2026:19875

Detections

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