Medium severity · published May 5, 2026
CVE-2026-34956
Openvswitch: open vswitch: denial of service via malformed ftp epasv command
5.9
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FD
Fast Datapath for RHEL 7 · Red Hat
All versions, or not specified · source: vendor
FD
Fast Datapath for RHEL 8 · Red Hat
All versions, or not specified · source: vendor
FD
Fast Datapath for RHEL 9 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat OpenShift Container Platform 4 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat OpenStack Platform 13 (Queens) · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat OpenStack Platform 16.2 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat OpenStack Platform 17.1 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat OpenStack Platform 18.0 · Red Hat
All versions, or not specified · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34956
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34956
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-34956
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2453459
www.openwall.com
http://www.openwall.com/lists/oss-security/2026/03/31/15
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