CVE-2026-34956

MEDIUM

Openvswitch: open vswitch: denial of service via malformed ftp epasv command

Title source: cna

Description

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.

References (3)

Core 3

Core References

Mailing List

http://www.openwall.com/lists/oss-security/2026/03/31/15

Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat

https://access.redhat.com/security/cve/CVE-2026-34956

Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat

RHBZ#2453459

https://bugzilla.redhat.com/show_bug.cgi?id=2453459

Scores

CVSS v3 5.9

EPSS 0.0013

EPSS Percentile 31.7%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-120

Status published

Products (9)

Red Hat/Fast Datapath for RHEL 7

Red Hat/Fast Datapath for RHEL 8

Red Hat/Fast Datapath for RHEL 9

Red Hat/Red Hat Enterprise Linux 7

Red Hat/Red Hat OpenShift Container Platform 4

Red Hat/Red Hat OpenStack Platform 13 (Queens)

Red Hat/Red Hat OpenStack Platform 16.2

Red Hat/Red Hat OpenStack Platform 17.1

Red Hat/Red Hat OpenStack Platform 18.0

Published May 05, 2026

Tracked Since May 05, 2026