RHEL 8 : kernel (RHSA-2026:26535)

high Nessus Plugin ID 321564

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-2026:26535 advisory.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

* kernel: geneve: Fix use-after-free in geneve_find_dev(). (CVE-2025-21858)

* kernel: sctp: fix a potential overflow in sctp_ifwdtsn_skip (CVE-2023-53372)

* kernel: net: use dst_dev_rcu() in sk_setup_caps() (CVE-2025-40170)

* kernel: ipv6: use RCU in ip6_xmit() (CVE-2025-40135)

* kernel: ipv6: use RCU in ip6_output() (CVE-2025-40158)

* kernel: nbd: defer config unlock in nbd_genl_connect (CVE-2025-68366)

* kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800)

* kernel: iommu: disable SVA when CONFIG_X86 is set (CVE-2025-71089)

* kernel: macvlan: fix possible UAF in macvlan_forward_source() (CVE-2026-23001)

* kernel: Linux kernel: Denial of Service due to a deadlock in hugetlb folio migration (CVE-2026-23097)

* kernel: ALSA: aloop: Fix racy access at PCM trigger (CVE-2026-23191)

* kernel: scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count() (CVE-2026-23216)

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

* kernel: netfilter: nf_tables: release flowtable after rcu grace period on error (CVE-2026-23392)

* kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets (CVE-2026-31685)

* kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037)

* kernel: ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach() (CVE-2026-43038)

* kernel: netfilter: ctnetlink: ensure safe access to master conntrack (CVE-2026-43116)

* kernel: wifi: brcmfmac: validate bsscfg indices in IF events (CVE-2026-43110)

* kernel: md/bitmap: fix GPF in write_page caused by resize race (CVE-2026-43163)

* kernel: netfilter: xt_tcpmss: check remaining length before reading optlen (CVE-2026-43190)

* kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks (CVE-2026-43158)

* kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243)

* kernel: sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL (CVE-2026-46227)

Bug Fix(es) and Enhancement(s):

* NFS client hangs while returning delegations (JIRA:RHEL-112276)

* Rhel backport of upstream commit i40e: avoid redundant VF link state update (JIRA:RHEL-141908)

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.

Plugin Details

Severity: High

ID: 321564

File Name: redhat-RHSA-2026-26535.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 6/20/2026

Updated: 6/20/2026

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

Risk Information

VPR

Risk Factor: High

Score: 7.4

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-23216

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-tools, cpe:/o:redhat:rhel_aus:8.4, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:perf

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: 6/17/2026

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2023-53372, CVE-2025-21858, CVE-2025-40135, CVE-2025-40158, CVE-2025-40170, CVE-2025-68366, CVE-2025-68800, CVE-2025-71089, CVE-2026-23001, CVE-2026-23097, CVE-2026-23191, CVE-2026-23216, CVE-2026-23243, CVE-2026-23392, CVE-2026-31685, CVE-2026-43037, CVE-2026-43038, CVE-2026-43110, CVE-2026-43116, CVE-2026-43158, CVE-2026-43163, CVE-2026-43190, CVE-2026-46227, CVE-2026-46243

CWE: 125, 1285, 1287, 131, 367, 413, 416, 617, 820, 825, 833, 843, 911

RHSA: 2026:26535

Detections

Analytics