SB2026100782 - Use-after-free in Linux kernel powerpc kvm



SB2026100782 - Use-after-free in Linux kernel powerpc kvm

Published: October 7, 2026

Security Bulletin ID SB2026100782
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-98283)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to trigger access to freed kernel memory.

The vulnerability exists due to use-after-free in kvmhv_emulate_tlbie_all_lpid() when iterating nested-guest entries and dropping mmu_lock without holding a reference to the nested-guest object. A local user can issue a concurrent single-LPID tlbie operation from another vCPU to trigger access to freed kernel memory.

The memory-release path is fully controlled by the L1 guest. The single-LPID operation uses is=2 and ric=2.


Remediation

Install update from vendor's website.