SB2026092217 - Red Hat Enterprise Linux 9 update for kernel



SB2026092217 - Red Hat Enterprise Linux 9 update for kernel

Published: September 22, 2026

Security Bulletin ID SB2026092217
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Improper Initialization (CVE-ID: CVE-2026-64368)

CWE-ID: CWE-665 - Improper Initialization

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to improper initialization in slab allocation handling in mm/slub.c when allocating kmalloc objects with zeroing enabled. A local user can trigger a memory allocation pattern that leaves part of the allocated object uninitialized to disclose sensitive information.

The issue occurs when requested-size tracking is not enabled while red zoning alone is enabled, which can break krealloc() __GFP_ZERO expectations.


2) Use-after-free (CVE-ID: CVE-2026-64564)

CWE-ID: CWE-416 - Use After Free

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 a use-after-free in sctp_process_asconf_param() when processing crafted SCTP ASCONF DEL-IP parameters. A remote attacker can send a specially crafted SCTP ASCONF message to cause a denial of service.

The issue can occur when a single ASCONF carries DEL-IP parameters that free the cached transport and a later wildcard DEL-IP reuses the dangling transport pointer.


Remediation

Install update from vendor's website.