Answer in brief
CVE-2026-34956 records a Medium severity (CVSS 5.9) vulnerability in Openvswitch: open vswitch: denial of service via malformed ftp epasv command. The current sources do not mark it as known exploited. The current feed maps Red Hat/openshift/ose-rhel-coreos-8 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic), Red Hat/openvswitch (generic), Red Hat/openvswitch2.10 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Red Hat/openshift/ose-rhel-coreos-8 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic), Red Hat/openvswitch (generic), Red Hat/openvswitch2.10 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Red Hat/openshift/ose-rhel-coreos-8generic | * | Not reported |
| Red Hat/openshift/ose-rhel-coreos-9generic | * | Not reported |
| Red Hat/openvswitchgeneric | * | Not reported |
| Red Hat/openvswitch2.10generic | * | Not reported |
| Red Hat/openvswitch2.11generic | * | Not reported |
| Red Hat/openvswitch2.12generic | * | Not reported |
| Red Hat/openvswitch2.13generic | * | Not reported |
| Red Hat/openvswitch2.15generic | * | Not reported |
| Red Hat/openvswitch2.16generic | * | Not reported |
| Red Hat/openvswitch2.17generic | * | Not reported |
| Red Hat/openvswitch3.0generic | * | Not reported |
| Red Hat/openvswitch3.1generic | * | Not reported |
| Red Hat/openvswitch3.2generic | * | Not reported |
| Red Hat/openvswitch3.3generic | * | Not reported |
| Red Hat/openvswitch3.4generic | * | Not reported |
| Red Hat/openvswitch3.5generic | * | Not reported |
| Red Hat/openvswitch3.6generic | * | Not reported |
| Red Hat/openvswitch-selinux-extra-policygeneric | * | Not reported |
| Red Hat/ovn2.11generic | * | Not reported |
| Red Hat/ovn2.12generic | * | Not reported |
| Red Hat/rhoso-openvswitchgeneric | * | Not reported |
| Red Hat/rhosp13/openstack-neutron-openvswitch-agentgeneric | * | Not reported |
| Red Hat/rhosp13/openstack-openvswitch-basegeneric | * | Not reported |
| Red Hat/rhosp13/openstack-ovn-basegeneric | * | Not reported |
| Red Hat/rhosp-openvswitchgeneric | * | Not reported |
| Red Hat/rhosp-rhel8/openstack-neutron-openvswitch-agentgeneric | * | Not reported |
| Red Hat/rhosp-rhel9/openstack-neutron-openvswitch-agentgeneric | * | Not reported |
Published upstream
May 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 21, 2026
A flaw was found in Open vSwitch. When Open vSwitch is configured with a conntrack flow using FTP helpers over the userspace datapath, a remote attacker can send a specially crafted FTP stream with an EPASV command exceeding 255 characters. This heap access error can lead to a crash, resulting in a Denial of Service (DoS) for the affected system.
Quoted source text, attributed separately from HOL analysis.