CVE-2026-93683

A flaw was found in the DPDK vhost library. When handling a virtio indirect descriptor table, the host reads the table length more than once from guest memory and can allocate a host copy before validating that length. A guest that changes the length between those reads, or that supplies an out-of-range next index on a small host copy in the vDPA relay path, can cause the host vhost process to walk past the validated mapping or heap copy. That can crash or disrupt the vhost process. Out-of-bounds bytes are consumed as descriptor fields for GPA translation and are not returned to the guest as payload. This is a residual issue in the non-contiguous indirect descriptor copy path introduced as part of the CVE-2018-1059 fix.

This Moderate flaw in the DPDK vhost library allows a malicious guest to cause a denial of service on the host vhost process. By manipulating the virtio indirect descriptor table length, a guest can trigger an out-of-bounds memory access, leading to a crash or disruption of the vhost process. This issue requires a compromised guest to exploit.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No runtime mitigation. QEMU indirect_desc=off does not help: libvhost honours VRING_DESC_F_INDIRECT anyway. Do not expose vhost-user to untrusted guests.