CentOS Linux 8.5 [TuxCare] Security Update: bpftool / kernel / kernel-core / kernel-cross-headers / etc Multiple Vulnerabilities (CENTOS8.5:CLSA-2026:1787572220)

critical Nessus Plugin ID 351684

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 8.5 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS8.5:CLSA-2026:1787572220 advisory.

- In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: add RCU protection to mld_newpack() mld_newpack() can be called without RTNL or RCU being held. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection. (CVE-2025-21758)

- In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: extend RCU protection in igmp6_send() igmp6_send() can be called without RTNL or RCU being held. Extend RCU protection so that we can safely fetch the net pointer and avoid a potential UAF. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection. (CVE-2025-21759)

- In the Linux kernel, the following vulnerability has been resolved: ndisc: extend RCU protection in ndisc_send_skb() ndisc_send_skb() can be called without RTNL or RCU held. Acquire rcu_read_lock() earlier, so that we can use dev_net_rcu() and avoid a potential UAF. (CVE-2025-21760)

- In the Linux kernel, the following vulnerability has been resolved: openvswitch: use RCU protection in ovs_vport_cmd_fill_info() ovs_vport_cmd_fill_info() can be called without RTNL or RCU. Use RCU protection and dev_net_rcu() to avoid potential UAF. (CVE-2025-21761)

- In the Linux kernel, the following vulnerability has been resolved: arp: use RCU protection in arp_xmit() arp_xmit() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF.
(CVE-2025-21762)

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 based on the guidance in TuxCare advisory CENTOS8.5:CLSA-2026:1787572220.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1787572220

http://www.nessus.org/u?9af649ce

Plugin Details

Severity: Critical

ID: 351684

File Name: tuxcare_centos_8.5_CLSA-2026-1787572220.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/30/2026

Updated: 9/30/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.36

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2026-23112

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/24/2026

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2025-21758, CVE-2025-21759, CVE-2025-21760, CVE-2025-21761, CVE-2025-21762, CVE-2025-21763, CVE-2025-21765, CVE-2026-23112, CVE-2026-31786, CVE-2026-31787, CVE-2026-43125, CVE-2026-43198, CVE-2026-64266, CVE-2026-64298, CVE-2026-64564, CVE-2026-68287

CLSA: 2026:1787572220