Use-after-free in Linux kernel - CVE-2026-31588
Published: April 25, 2026
Vulnerability identifier: #VU127814
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-31588
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
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.
How to mitigate CVE-2026-31588
Install security update from vendor's repository.