Improper access control in Linux kernel - CVE-2026-64285
Published: July 27, 2026
Vulnerability identifier: #VU139697
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64285
CWE-ID: CWE-284
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to corrupt read-only memory.
The vulnerability exists due to improper access control in guest_memfd population for SNP guest CPUID data when populating a guest_memfd instance from a user-supplied source page. A local user can provide CPUID data backed by a read-only mapping to corrupt read-only memory.
Exploitation requires the source page to be used for initial CPUID data for an SNP guest, and well-behaved VMMs are unlikely to be affected because such CPUID data is typically generated dynamically by userspace.
Affected software
Linux kernel
How to mitigate CVE-2026-64285
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3