CVE-2026-34956
Openvswitch: open vswitch: denial of service via malformed ftp epasv command
No known exploitation. EPSS puts it in the 48th percentile. Only a workaround so far.
What to do
No fixed build is published yet. The vendor describes a workaround.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 48th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
12 events over 119 days, from the signal feeds we watch.
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- OpenVAS check added
- Workaround availablepublished, weakness classified, att&ck mapped, record updated
Affected products
- Fast Datapath for RHEL 7Operating Systems / linux-distro
- Fast Datapath for RHEL 8Operating Systems / linux-distro
- Fast Datapath for RHEL 9Operating Systems / linux-distro
- Red Hat Enterprise Linux 7Operating Systems / linux-distro
- Red Hat OpenShift Container Platform 4Cloud & SaaS / container-orchestration
- Red Hat OpenStack Platform 13 (Queens)Cloud & SaaS / cloud-platform
- Red Hat OpenStack Platform 16.2Cloud & SaaS / cloud-platform
- Red Hat OpenStack Platform 17.1Cloud & SaaS / cloud-platform
And 1 more affected product. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Scored 5.9 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
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