Type Mismatch Vulnerability in QEMU's Vhost Inflight Migration
CVE-2026-6426

4.4MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
10 August 2026

What is CVE-2026-6426?

A type mismatch vulnerability exists in QEMU's vhost inflight migration VMState handling. This vulnerability is caused by the destination buffer size being stored as a uint64_t but read as a signed int32_t in the VMS_VBUFFER load path. When a crafted migration state is encountered on little-endian hosts, bit 31 can lead to negative interpretation, which can result in an expansive and unsafe memory allocation. As a consequence, the function qemu_get_buffer() may copy migration-stream data beyond the intended mmap-backed region, causing potential crashes or memory corruption. Successful exploitation necessitates control over the migration producer and write access to the migration channel, alongside a destination set up for vhost inflight migration.

References

https://access.redhat.com/security/cve/CVE-2026-6426
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2513498
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
4.4
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
High
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Seungjung Kim (Kyonggi University) for reporting this issue.
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