SB20260425132 - Use-after-free in Linux kernel complete_emulated_mmio()
Published: April 25, 2026
Security Bulletin ID
SB20260425132
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-31588)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/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 use-after-free in complete_emulated_mmio() when servicing an emulated MMIO write that splits a page boundary across MMIO pages. A local user can trigger crafted KVM_RUN operations to cause a denial of service.
The issue occurs for write payloads of 8 bytes or less and is most visible when the second KVM_RUN is performed by a separate task.
Remediation
Install update from vendor's website.