CVE-2026-34956

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 v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

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

Configurations

No configuration.

History

No history.

Information

Published : 2026-05-05 16:16

Updated : 2026-09-01 13:18

NVD link : CVE-2026-34956

Mitre link : CVE-2026-34956

CVE.ORG link : CVE-2026-34956

JSON object : View

Products Affected

No product.

CWE

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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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."}], "lastModified": "2026-09-01T13:18:58.630", "sourceIdentifier": "secalert@redhat.com"}