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CVE-2026-34956

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

Published: May 5, 2026Updated: May 5, 2026 Sources: CVE List NVDCWE-120
5.9MEDIUM
NVD MITRE
EPSS Score
0.4%
Top 66.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-120

Affected Products

Red Hat
commercial·US
Fast Datapath for RHEL 7On-premLibrary
Operating Systems / linux-distro
Fast Datapath for RHEL 8On-premLibrary
Operating Systems / linux-distro
Fast Datapath for RHEL 9On-premLibrary
Operating Systems / linux-distro
Red Hat Enterprise Linux 7On-premOS
Operating Systems / linux-distro
Red Hat OpenShift Container Platform 4SaaSSaaS Service
Cloud & SaaS / container-orchestration
Red Hat OpenStack Platform 13 (Queens)On-prem
Cloud & SaaS / cloud-platform
Red Hat OpenStack Platform 16.2On-prem
Cloud & SaaS / cloud-platform
Red Hat OpenStack Platform 17.1SaaSSaaS Service
Cloud & SaaS / cloud-platform
and 1 more affected products View all →

Exploitability

Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://access.redhat.com/security/cve/CVE-2026-34956
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2453459
bugzilla.redhat.com
http://www.openwall.com/lists/oss-security/2026/03/31/15
openwall.com

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