CVE-2025-8860 — Qemu-kvm: uefi-vars: information disclosure vulnerability in uefi_vars_write callback
A flaw was found in QEMU in the uefi-vars virtual device. When the guest writes to register UEFI_VARS_REG_BUFFER_SIZE, the .write callback `uefi_vars_write` is invoked. The func…
Published: 2026-02-18 · CVSS: 3.3 · CVSS 3.1
A flaw was found in QEMU in the uefi-vars virtual device. When the guest writes to register UEFI_VARS_REG_BUFFER_SIZE, the .write callback `uefi_vars_write` is invoked. The function allocates a heap buffer without zeroing the memory, leaving the buffer filled with residual data from prior allocations. When the guest later reads from register UEFI_VARS_REG_PIO_BUFFER_TRANSFER, the .read callback `uefi_vars_read` returns leftover metadata or other sensitive process memory from the previously allocated buffer, leading to an information disclosure vulnerability.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7