# CVE-2026-86566: Dpdk: dpdk: guest with runt rx descriptors underflows copy length in vhost enqueue (split and packed rings)

Status: published. Published: 2026-10-14. Updated: 2026-11-06.

A flaw was found in DPDK lib/vhost. A guest with runt RX descriptors can underflow the copy length in vhost enqueue, causing a denial of service in a shared vhost backend such as OVS-DPDK.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. (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 (grout): Version range not reported. 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 (grout): 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: 6.5 (medium); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H; source: CNA: redhat

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.17% as of 2026-11-05; percentile 6.51%

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

- Weaknesses: CWE-191

## 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-2026-86566 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2529684 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:94629 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:94630 (secalert@redhat.com)

- https://access.redhat.com/security/cve/CVE-2026-86566 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2529684 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-86566; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86566; retrieved 2026-11-04; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-86566; retrieved 2026-11-06; source updated Not reported

Revision: 3528cdec2b9ed44747e0244eb015f0ace8c3ec60d3bc1e9b80d92d274d1ab987

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