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CVE-2023-5366: A flaw was found in Open vSwitch that allows ICMPv6 Neighbor Advertisement packets between virtual machines to

39
Routine
HIGH 7.1WATCHLISTUPGRADEDOWNGRADEDOWNGRADE

CVE-2023-5366 is a high-severity flaw (CVSS 7.1) affecting openvswitch, openshift container platform, virtualization. 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 that allows ICMPv6 Neighbor Advertisement packets between virtual machines to bypass OpenFlow rules. This issue may allow a local attacker to create specially crafted packets with a modified or spoofed target IP address field that can redirect ICMPv6 traffic to arbitrary IP addresses.

Why this priority

  • High severity
  • On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score7.1 (High)
Attack vectorNetwork (remote)
Attack complexityLow
Privileges neededLow
User interactionNone
EPSS exploit chance0.4% (top 64%)
CISA exploited listNo
WeaknessCWE-345
Published2023-10-06
Last modified2026-06-17
Publisher (CNA): Red Hat, Inc. · Vendor: openvswitch · redhat

Share: LinkedIn · X · Reddit

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

Am I affected?

Timeline

openvswitch openvswitch UPGRADE
Affected: < 2023-02-28
Fixed in: 2023-02-28
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy openvswitch || rpm -q openvswitch || openvswitch --version
2. UPGRADE to 2023-02-28 (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.
redhat openshift container platform DOWNGRADE
Affected: 4.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.0
1. Check installed version
apt-cache policy openshift-container-platform || rpm -q openshift-container-platform || openshift-container-platform --version
2. No fixed release: DOWNGRADE to a release before 4.0 (Debian / Ubuntu)
apt-cache madison openshift-container-platform sudo apt install openshift-container-platform=<VERSION_BEFORE_4.0> sudo apt-mark hold openshift-container-platform
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list openshift-container-platform sudo dnf downgrade openshift-container-platform-<VERSION_BEFORE_4.0> sudo dnf versionlock add openshift-container-platform
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
redhat virtualization DOWNGRADE
Affected: 4.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.0
1. Check installed version
apt-cache policy virtualization || rpm -q virtualization || virtualization --version
2. No fixed release: DOWNGRADE to a release before 4.0 (Debian / Ubuntu)
apt-cache madison virtualization sudo apt install virtualization=<VERSION_BEFORE_4.0> sudo apt-mark hold virtualization
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list virtualization sudo dnf downgrade virtualization-<VERSION_BEFORE_4.0> sudo dnf versionlock add virtualization
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
redhat enterprise linux MITIGATE
Affected: 7.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 7.0
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.
redhat fast datapath MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy fast-datapath || rpm -q fast-datapath || fast-datapath --version
No fixed or unaffected release known
Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.
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-2023-5366?

openvswitch: upgrade to 2023-02-28; openshift container platform: downgrade or apply the listed mitigation; virtualization: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-5366 being exploited?

CVE-2023-5366 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-2023-5366 affect?

CVE-2023-5366 affects openvswitch, openshift container platform, virtualization. Severity is high (CVSS 7.1). A flaw was found in Open vSwitch that allows ICMPv6 Neighbor Advertisement packets between virtual machines to bypass OpenFlow rules. This issue may allow a local attacker to create specially crafted packets with a modified or spoofed targe

How urgent is CVE-2023-5366?

Priority 39/100. High severity; On your watchlist

Software pages

Red Hat OpenShift vulnerabilities

Related CVEs

References

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