CVE-2023-3966: A flaw was found in Open vSwitch where multiple versions are vulnerable to crafted Geneve packets, which may r

Q: How do I fix CVE-2023-3966?

openvswitch: upgrade to 3.1.0; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2023-3966 being exploited?

CVE-2023-3966 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-3966 affect?

CVE-2023-3966 affects openvswitch, fedora. Severity is high (CVSS 7.5). A flaw was found in Open vSwitch where multiple versions are vulnerable to crafted Geneve packets, which may result in a denial of service and invalid memory accesses. Triggering this issue requires that hardware offloading via the netlink

Q: How urgent is CVE-2023-3966?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADEMITIGATE

CVE-2023-3966 is a high-severity flaw (CVSS 7.5) affecting openvswitch, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in Open vSwitch where multiple versions are vulnerable to crafted Geneve packets, which may result in a denial of service and invalid memory accesses. Triggering this issue requires that hardware offloading via the netlink path is enabled.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 36%)
CISA exploited list	No
Weakness	CWE-248
Published	2024-02-22
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: fedoraproject · openvswitch

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-02-22 13:15 UTCPublished CVE record published
2026-06-17 06:15 UTCUpdated Record last modified

openvswitch openvswitch UPGRADE

Affected: < 3.1.0

Fixed in: 3.1.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy openvswitch || rpm -q openvswitch || openvswitch --version

2. UPGRADE to 3.1.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openvswitch

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openvswitch

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

fedoraproject fedora MITIGATE

Affected: 39 · 40

Fixed in: no fixed release known

Safe to downgrade to: a release before 39

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-3966?

openvswitch: upgrade to 3.1.0; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-3966 being exploited?

CVE-2023-3966 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-3966 affect?

CVE-2023-3966 affects openvswitch, fedora. Severity is high (CVSS 7.5). A flaw was found in Open vSwitch where multiple versions are vulnerable to crafted Geneve packets, which may result in a denial of service and invalid memory accesses. Triggering this issue requires that hardware offloading via the netlink

How urgent is CVE-2023-3966?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2024-22563 HIGH 7.5 DOWNGRADE openvswitch 2.17.8 was discovered to contain a memory leak via the function xmalloc__ in openvswitch-2.17.8/li
CVE-2023-5366 HIGH 7.1 UPGRADE DOWNGRADE A flaw was found in Open vSwitch that allows ICMPv6 Neighbor Advertisement packets between virtual machines to

References

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