# CVE-2026-93683: Dpdk: dpdk: guest-triggered out-of-bounds walk via vhost indirect descriptor length toctou

Status: published. Published: 2026-10-14. Updated: 2026-11-03.

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.

## Remediation

- workaround: 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. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (dpdk): ≥ 2:25.11-2.el10_2; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (dpdk): ≥ 2:25.11-2.el9_8; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 10 (openvswitch3.5): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 10 (openvswitch3.6): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.11): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.12): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.13): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.15): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.16): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch2.17): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 8 (openvswitch3.1): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch2.17): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.0): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.1): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.2): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.3): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.4): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.5): Version range not reported. Source: CNA: redhat
- Red Hat / Fast Datapath for RHEL 9 (openvswitch3.6): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (dpdk): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openvswitch2.17): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openvswitch3.0): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openvswitch3.1): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenStack Platform 13 (Queens) (openvswitch): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.4 (medium); CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.10% as of 2026-11-03; percentile 0.87%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-367

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:94629 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:94630 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-93683 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2537015 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-93683; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-93683; retrieved 2026-11-03; source updated Not reported

Revision: 9b67a53f814349e434f876ef762da6a50e60c0ac8af1a35bdc0a487c7509a30d

Canonical: https://y2.dev/cve/CVE-2026-93683

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