CVE-2026-5164: Virtio-win: virtio-win: denial of service via unvalidated descriptor count in unmap request

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-30 · updated 2026-06-17
Weakness: CWE-120

Description

A flaw was found in virtio-win. The `RhelDoUnMap()` function does not properly validate the number of descriptors provided by a user during an unmap request. A local user could exploit this input validation vulnerability by supplying an excessive number of descriptors, leading to a buffer overrun. This can cause a system crash, resulting in a Denial of Service (DoS).

Affected products

Red Hat Enterprise Linux: 9.0, 10.0
RedHat Virtio-Win: all versions

References

https://access.redhat.com/security/cve/CVE-2026-5164
https://bugzilla.redhat.com/show_bug.cgi?id=2453014
https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1504

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