CVE-2026-6426
Published: August 11, 2026Last modified: November 6, 2026
Description
A type mismatch vulnerability was found in QEMU's vhost inflight migration VMState handling. The destination buffer size is stored as a uint64_t but read by the VMS_VBUFFER load path as a signed int32_t. On little-endian hosts, a crafted incoming migration state with bit 31 set causes the value to be interpreted as negative and then implicitly converted to a very large size_t, leading qemu_get_buffer() to copy migration-stream data beyond the bounds of the mmap-backed inflight region. This can result in a crash of the QEMU process or memory corruption. Exploitation requires control of the migration producer or write access to the migration channel, combined with a destination configured to use vhost inflight migration.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4.4 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | HIGH |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | qemu | Unknown (7.1.0-r4) |
| 25 LTS | qemu | Unknown (10.0.0-r1) | |
| Stream | qemu | Fixed (11.1.3-r0) |