SB20260824265 - Red Hat Enterprise Linux 8 update for kernel

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Main Vulnerability Database SB20260824265

SB20260824265 - Red Hat Enterprise Linux 8 update for kernel

Published: August 24, 2026

Security Bulletin ID SB20260824265
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Resource management error (CVE-ID: CVE-2025-40026)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to resource management error within the emulator_is_smm() and x86_emulate_instruction() functions in arch/x86/kvm/x86.c. A local user can perform a denial of service (DoS) attack.


2) Out-of-bounds write (CVE-ID: CVE-2026-43125)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an out-of-bounds write in dlm_search_rsb_tree() when processing network messages with an excessive resource name length. A remote attacker can send a specially crafted network message to cause a denial of service.

The length value originates from the len parameter in dlm_dump_rsb_name().


3) Improper privilege management (CVE-ID: CVE-2025-54518)

CWE-ID: CWE-269 - Improper Privilege Management

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to improper privilege management in x86 CPU opcode cache handling when executing code on affected AMD Fam17h CPUs. A local user can execute code to escalate privileges.

The issue can permit escalation across privilege boundaries including userspace to kernel and guest to host, and only AMD Fam17h CPUs based on the Zen2 microarchitecture are believed to be affected.


4) Improper access control (CVE-ID: CVE-2026-46054)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to bypass SELinux access controls.

The vulnerability exists due to improper access control in SELinux overlayfs mmap() and mprotect() access checks when handling mmap() and mprotect() operations on overlayfs filesystems. A local user can map or change protections on an overlayfs file to bypass SELinux access controls.


Remediation

Install update from vendor's website.

References