SB2026070904 - Red Hat Enterprise Linux 9 update for kernel
Published: July 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2025-71066)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the ets_qdisc_change() function in net/sched/sch_ets.c. A local user can escalate privileges on the system.
2) Use-after-free (CVE-ID: CVE-2026-46113)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in KVM shadow paging when handling guest page table changes between VM entries. A local user can modify guest page tables to create a stale reverse-mapping entry and trigger a stale rmap walk to cause a denial of service.
This can be triggered during operations such as dirty logging or MMU notifier invalidations.
3) Use-after-free (CVE-ID: CVE-2026-53359)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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/E:U/U:Clear
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.