SB2026080635 - Red Hat Enterprise Linux 9 update for kernel



SB2026080635 - Red Hat Enterprise Linux 9 update for kernel

Published: August 6, 2026

Security Bulletin ID SB2026080635
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2026-23415)

CWE-ID: CWE-416 - Use After Free

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 cause a denial of service.

The vulnerability exists due to use-after-free in __futex_key_to_node() when processing futex operations during a race with vma policy replacement. A local user can trigger concurrent futex activity and memory policy changes to cause a denial of service.

The issue is caused by a race between futex_key_to_node_opt() and vma_replace_policy() that leads to a use-after-free read of mpol->mode from a freed mempolicy pointer.


2) Out-of-bounds read (CVE-ID: CVE-2026-43450)

CWE-ID: CWE-125 - Out-of-bounds read

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 cause a denial of service.

The vulnerability exists due to out-of-bounds read in nfnl_cthelper_dump_table() when handling netlink dump requests after a previously saved helper entry is deleted between dump rounds. A local user can trigger the affected dump logic to cause a denial of service.

The issue is triggered when the saved "last" helper is deleted between dump rounds, causing a restart path to bypass the loop bounds check.


Remediation

Install update from vendor's website.