SB2026072306 - Red Hat Enterprise Linux 10 update for kpatch-patch-6_12_0-211_16_1



SB2026072306 - Red Hat Enterprise Linux 10 update for kpatch-patch-6_12_0-211_16_1

Published: July 23, 2026

Security Bulletin ID SB2026072306
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2026-46242)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to a use-after-free in ep_remove() in fs/eventpoll.c when removing epoll file references during a race with file release handling. A local user can trigger a race condition to cause memory corruption.

The issue involves the epoll-watches-epoll case and a concurrent __fput() path that can lead to operations on freed structures.


2) Out-of-bounds write (CVE-ID: CVE-2026-53362)

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

CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to corrupt kernel memory.

The vulnerability exists due to an out-of-bounds write in __ip6_append_data() when processing UDPv6 socket data with MSG_MORE and MSG_SPLICE_PAGES on the paged allocation path. A local user can send crafted data through a UDPv6 socket to corrupt kernel memory.

The issue occurs when fraggap is non-zero and the paged-allocation branch is taken, causing writes past skb->end into trailing skb_shared_info.


3) Use-after-free (CVE-ID: CVE-2026-53359)

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 the KVM x86 shadow paging logic when changing a PDE mapping from outside the guest and deleting a memslot. A local user can trigger stale rmap entries and subsequent dereference of a freed sptep to cause a denial of service.

The issue occurs when a modified PDE points to a non-leaf page, causing a role mismatch between reused shadow pages for large 2MB mappings and new 4KB mappings.


Remediation

Install update from vendor's website.