CVE-2026-34956: Open vSwitch · Buffer Overflow
Source GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 27 Oct 2026, 00:07 UTC
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Fast Datapath for RHEL 7openvswitch | Affected– | Fixed in– |
| Fast Datapath for RHEL 7openvswitch2.10 | Affected– | Fixed in– |
| Fast Datapath for RHEL 7openvswitch2.11 | Affected– | Fixed in– |
| Fast Datapath for RHEL 7openvswitch2.12 | Affected– | Fixed in– |
| Fast Datapath for RHEL 7openvswitch2.13 | Affected– | Fixed in– |
| Fast Datapath for RHEL 7openvswitch-selinux-extra-policy | Affected– | Fixed in– |
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.