RHEL 8 : kernel-rt (RHSA-2026:55765)

high Nessus Plugin ID 335994

Synopsis

The remote Red Hat host is missing one or more security updates.

Description

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:55765 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: mm/slub: avoid accessing metadata when pointer is invalid in object_err() (CVE-2025-39902)

* kernel: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() (CVE-2026-43206)

* kernel: crypto: ccp - copy IV using skcipher ivsize (CVE-2026-53016)

* kernel: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size (CVE-2026-53136)

* kernel: drm/amd/display: Use krealloc_array() in dal_vector_reserve() (CVE-2026-53329)

* kernel: drm/amdgpu: zero-initialize GART table on allocation (CVE-2026-53374)

* kernel: drm/i915: Fix potential UAF in TTM object purge (CVE-2026-63884)

* kernel: drm/amdgpu: fix amdgpu_hmm_range_get_pages (CVE-2026-63879)

* kernel: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async (CVE-2026-64219)

* kernel: can:bcm: arbitrary kernel code execution leading to escalate privileges (CVE-2026-17523)

Bug Fix(es) and Enhancement(s):

* Backport sched/deadline: Fix bandwidth reclaim equation in GRUB to RHEL 8.10 (JIRA:RHEL-189997)

* vhost: reset the vring metadata cache on vring reconfiguration [rhel-8.10.z] (JIRA:RHEL-224556)

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 affected packages.

See Also

https://access.redhat.com/errata/RHSA-2026:55765

https://access.redhat.com/security/updates/classification/#important

https://bugzilla.redhat.com/show_bug.cgi?id=2400594

https://bugzilla.redhat.com/show_bug.cgi?id=2467156

https://bugzilla.redhat.com/show_bug.cgi?id=2492269

https://bugzilla.redhat.com/show_bug.cgi?id=2492768

https://bugzilla.redhat.com/show_bug.cgi?id=2495941

https://bugzilla.redhat.com/show_bug.cgi?id=2502188

https://bugzilla.redhat.com/show_bug.cgi?id=2502321

https://bugzilla.redhat.com/show_bug.cgi?id=2502463

https://bugzilla.redhat.com/show_bug.cgi?id=2506790

https://bugzilla.redhat.com/show_bug.cgi?id=2507407

http://www.nessus.org/u?98e53b69

Plugin Details

Severity: High

ID: 335994

File Name: redhat-RHSA-2026-55765.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.8

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-53136

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:rhel_eus:8.10, 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-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-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 Ease: No known exploits are available

Patch Publication Date: 8/17/2026

Vulnerability Publication Date: 9/22/2025

Reference Information

CVE: CVE-2025-39902, CVE-2026-17523, CVE-2026-43206, CVE-2026-53016, CVE-2026-53136, CVE-2026-53329, CVE-2026-53374, CVE-2026-63879, CVE-2026-63884, CVE-2026-64219

CWE: 120, 1284, 787, 805, 824, 825

RHSA: 2026:55765