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Full vulnerability report · 2026
CVE-2026-5367High confidence

Ovn: ovn: information disclosure via crafted dhcpv6 packets

Red Hat · Fast Datapath for Red Hat Enterprise Linux 10

8.6HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archiveovnUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 4 Sept 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-5367 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityovn: OVN: Information disclosure via crafted DHCPv6 packets
30 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • ovn23.03 as a component of Fast Datapath for RHEL 8
  • ovn23.03-central as a component of Fast Datapath for RHEL 8
  • ovn23.03-host as a component of Fast Datapath for RHEL 8
  • ovn23.03-vtep as a component of Fast Datapath for RHEL 8
  • ovn23.03.src as a component of Fast Datapath for RHEL 8
  • ovn-2021-central as a component of Fast Datapath for RHEL 9
  • ovn-2021-host as a component of Fast Datapath for RHEL 9
  • ovn-2021-vtep as a component of Fast Datapath for RHEL 9
  • ovn-2021.src as a component of Fast Datapath for RHEL 9
  • ovn23.03 as a component of Fast Datapath for RHEL 9
  • ovn23.03-central as a component of Fast Datapath for RHEL 9
  • ovn23.03-host as a component of Fast Datapath for RHEL 9
Summary
A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-25421

No EUVD known-exploited evidence

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
8.6 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

What

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

Why

The product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

What

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

Why

The product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Handling of Length Parameter Inconsistency → obtain information outside the intended access boundary
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-130 ↗

CWE-130: Improper Handling of Length Parameter Inconsistency. The product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-130
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-25421Official EUVD mapping

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

Official EUVD record
BSI · German · WID-SEC-W-2026-1315Fast Datapath für Red Hat Enterprise Linux (ovn): Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Fast Datapath für Red Hat Enterprise Linuxausnutzen, um einen Denial of Service Angriff durchzuführen oder vertrauliche Informationen offenzulegen.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
ovn23.03 as a component of Fast Datapath for RHEL 8; ovn23.03-central as a component of Fast Datapath for RHEL 8; ovn23.03-host as a component of Fast Datapath for RHEL 8; ovn23.03-vtep as a component of Fast Datapath for RHEL 8; ovn23.03.src as a component of Fast Datapath for RHEL 8; ovn-2021-central as a component of Fast Datapath for RHEL 9; ovn-2021-host as a component of Fast Datapath for RHEL 9; ovn-2021-vtep as a component of Fast Datapath for RHEL 9; ovn-2021.src as a component of Fast Datapath for RHEL 9; ovn23.03 as a component of Fast Datapath for RHEL 9; ovn23.03-central as a component of Fast Datapath for RHEL 9; ovn23.03-host as a component of Fast Datapath for RHEL 9; ovn23.03-vtep as a component of Fast Datapath for RHEL 9; ovn23.03.src as a component of Fast Datapath for RHEL 9; ovn23.06 as a component of Red Hat OpenShift Container Platform 4; ovn23.06-central as a component of Red Hat OpenShift Container Platform 4; ovn23.06-host as a component of Red Hat OpenShift Container Platform 4; ovn23.06-vtep as a component of Red Hat OpenShift Container Platform 4; ovn23.06.src as a component of Red Hat OpenShift Container Platform 4; ovn24.03 as a component of Red Hat OpenShift Container Platform 4; ovn24.03-central as a component of Red Hat OpenShift Container Platform 4; ovn24.03-host as a component of Red Hat OpenShift Container Platform 4; ovn24.03-vtep as a component of Red Hat OpenShift Container Platform 4; ovn24.03.src as a component of Red Hat OpenShift Container Platform 4; ovn24.09 as a component of Red Hat OpenShift Container Platform 4; ovn24.09-central as a component of Red Hat OpenShift Container Platform 4; ovn24.09-host as a component of Red Hat OpenShift Container Platform 4; ovn24.09-vtep as a component of Red Hat OpenShift Container Platform 4; ovn24.09.src as a component of Red Hat OpenShift Container Platform 4; ovn25.03.src as a component of Red Hat OpenShift Container Platform 4
Fixed
ovn25.03-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-0:25.03.2-100.el10fdp.src as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-debuginfo-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-debuginfo-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-debuginfo-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-central-debuginfo-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debuginfo-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debuginfo-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debuginfo-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debuginfo-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debugsource-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debugsource-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debugsource-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-debugsource-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-debuginfo-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-debuginfo-0:25.03.2-100.el10fdp.ppc64le as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-debuginfo-0:25.03.2-100.el10fdp.s390x as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-host-debuginfo-0:25.03.2-100.el10fdp.x86_64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; ovn25.03-vtep-0:25.03.2-100.el10fdp.aarch64 as a component of Fast Datapath for Red Hat Enterprise Linux 10; and 303 more
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 24 Apr 2026 · Last source change 25 Aug 2026, 12:05 UTC · CWE-130 · Improper Handling of Length Parameter Inconsistency

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-25421
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-25421↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-5367 · cve.blacktree.nl