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.

Score

CVSS 3.1 5.9 Medium

Status

Awaiting Analysis - secalert@redhat.com

Published

2026-05-05

Last modified

2026-10-26

Weaknesses

CWE-120

Affected products

• Enterprise Linux (Redhat)
• Openshift (Redhat)
• Openstack (Redhat)

References

• 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