What is CVE-2026-6426?
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.
The record classifies CVE-2026-6426 under weakness class CWE-681. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on availability. 7 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 56 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 4.4 — MEDIUM
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H - CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 2.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-08-10
Is CVE-2026-6426 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
- Red Hat: Enterprise Linux 10, Enterprise Linux 6, Enterprise Linux 7, Enterprise Linux 8, Enterprise Linux 9, Enterprise Linux for NVIDIA 26, OpenShift Container Platform 4
How to fix CVE-2026-6426
No vendor patch reference has been recorded for CVE-2026-6426 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-6426
No threat campaign in the Threadlinqs corpus currently references CVE-2026-6426, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org. Last verified by Threadlinqs on .