Memory Access Vulnerability in Linux Kernel on KVM-enabled Hosts

CVE-2026-80853

What is CVE-2026-80853?

In the Linux kernel, a vulnerability has been identified that affects KVM (Kernel-based Virtual Machine) on SEV (Secure Encrypted Virtualization) and SEV-ES (Secure Encrypted Virtualization-Encrypted State) guests hosted on SNP (Secure Nested Paging)-compatible platforms. This vulnerability stems from the failure to allocate full 4KiB pages for temporary buffers used in memory encryption and decryption operations. When transferring page ownership to firmware, the resulting inaccessibility to software can trigger unexpected memory access violations. This could lead to kernel panics and other operational disruptions due to concurrent memory allocations by other kernel processes. The resolution entails ensuring that proper page allocation practices are followed during cryptographic operations to maintain system integrity and stability.

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