CVE-2026-34956CWE-120

CVE-2026-34956

Medium · published May 5, 2026

CVSS v3.1
5.9
EPSS
1%
Percentile
49.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00635 · 49.8th percentile
Weakness
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Published
2026-05-05T20:16Z
References (3)
https://access.redhat.com/security/cve/CVE-2026-34956 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2453459 · [email protected]http://www.openwall.com/lists/oss-security/2026/03/31/15 · af854a3a-2127-422b-91ae-364da2661108
EPSS history
Timeline
  • 05 MAY 15:45Z
    Openvswitch: open vswitch: denial of service via malformed ftp epasv command
    cvelistv5