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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Fast Datapath for RHEL 7 | — | — |
| Red Hat | Fast Datapath for RHEL 8 | — | — |
| Red Hat | Fast Datapath for RHEL 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
| Red Hat | Red Hat OpenStack Platform 13 (Queens) | — | — |
| Red Hat | Red Hat OpenStack Platform 16.2 | — | — |
| Red Hat | Red Hat OpenStack Platform 17.1 | — | — |
| Red Hat | Red Hat OpenStack Platform 18.0 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openvswitch | 3.7.1-1 | — |
| Debian 13 | openvswitch | No fix yet | — |
| Debian 12 | openvswitch | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | openvswitch | No fix yet | — |
| Ubuntu 25.10 | openvswitch | No fix yet | — |
| Ubuntu 24.04 LTS | openvswitch | No fix yet | — |
| Ubuntu 22.04 LTS | openvswitch | No fix yet | — |
| Ubuntu 20.04 LTS | openvswitch | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | openvswitch | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | openvswitch | 3.5.4-150700.41.15.1 | SUSE-SU-2026:1439-1 |
| SLES 12 SP5 | openvswitch | 2.11.5-3.30.1 | SUSE-SU-2026:1482-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | openvswitch | 3.5.4-160000.4.1 | SUSE-SU-2026:22152-1 |
| SLES 16.0 | openvswitch | 3.5.4-160000.4.1 | SUSE-SU-2026:22152-1 |
| SLE Micro 6.2 | openvswitch | 3.5.4-160000.4.1 | SUSE-SU-2026:22145-1 |
| SLE Micro 6.1 | openvswitch | 3.1.7-slfo.1.1_3.1 | SUSE-SU-2026:22068-1 |
| SLE Micro 6.0 | openvswitch | 3.1.7-5.1 | SUSE-SU-2026:21250-1 |
| SLE Micro 5.5 | openvswitch3 | 3.1.7-150500.3.28.1 | SUSE-SU-2026:1440-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | openvswitch | 3.7.1-33.1 | openSUSE-SU-2026:10534-1 |
| openSUSE Leap 16.0 | openvswitch | 3.5.4-160000.4.1 | openSUSE-SU-2026:20972-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | openvswitch | 3.3.0-3 | — |
Advisories 9
- SUSE-SU-2026:22152-1 Security update for openvswitch SUSE / openSUSE Security Updates · Jun 24, 2026
- openSUSE-SU-2026:20972-1 Security update for openvswitch SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:22145-1 Security update for openvswitch SUSE / openSUSE Security Updates · Jun 19, 2026
- SUSE-SU-2026:22068-1 Security update for openvswitch SUSE / openSUSE Security Updates · Jun 13, 2026
- SUSE-SU-2026:21250-1 Security update for openvswitch SUSE / openSUSE Security Updates · Apr 24, 2026
- SUSE-SU-2026:1482-1 Security update for openvswitch SUSE / openSUSE Security Updates · Apr 21, 2026
- SUSE-SU-2026:1439-1 Security update for openvswitch SUSE / openSUSE Security Updates · Apr 18, 2026
- SUSE-SU-2026:1440-1 Security update for openvswitch3 SUSE / openSUSE Security Updates · Apr 18, 2026
- openSUSE-SU-2026:10534-1 libopenvswitch-3_7-0-3.7.1-33.1 on GA media SUSE / openSUSE Security Updates · Apr 12, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-34956 vdb-entry
- RHBZ#2453459 issue-tracking