SB2026090339 - Red Hat Enterprise Linux 7 Extended Lifecycle Support update for kernel-rt



SB2026090339 - Red Hat Enterprise Linux 7 Extended Lifecycle Support update for kernel-rt

Published: September 3, 2026

Security Bulletin ID SB2026090339
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 5
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 5 vulnerabilities.


1) Memory leak (CVE-ID: CVE-2023-52924)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: 5.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:U/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 memory leak within the nft_rbtree_walk() function in net/netfilter/nft_set_rbtree.c, within the nft_rhash_walk() function in net/netfilter/nft_set_hash.c, within the nf_tables_dump_setelem() function in net/netfilter/nf_tables_api.c. A local user can perform a denial of service (DoS) attack.


2) Use-after-free (CVE-ID: CVE-2026-43116)

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 a use-after-free in netfilter ctnetlink expectation handling when processing expectation add, delete, get, or event operations. A local user can trigger access to an invalid master conntrack object to cause a denial of service.


3) Use-after-free (CVE-ID: CVE-2026-45984)

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 gfs2 inline data write path when handling inline data writes. A local user can trigger an inline write operation to cause a denial of service.

The issue occurs because a buffer head is released before the inline write completes, leaving a stale pointer that is later dereferenced during the write end path.


4) Use-after-free (CVE-ID: CVE-2026-52923)

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 a use-after-free in ipc_idr_alloc() in the checkpoint/restore SysV IPC allocation path when processing a request for the next SysV IPC id. A local user can request allocation beyond the valid IPC id range to cause a denial of service.

A subsequent walk of /proc/sysvipc/shm can dereference freed memory through a stale IDR entry.


5) Out-of-bounds write (CVE-ID: CVE-2026-53059)

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

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 an out-of-bounds write in create_log_context() and dm-log bitset handling when processing a crafted device-mapper mirror target configuration with an oversized region count. A local user can create a crafted mirror target to cause a denial of service.

The issue is triggered when region_count overflows 32 bits, causing bitsets to be allocated smaller than required and later accessed with indices derived from the full region space.


Remediation

Install update from vendor's website.