Published severityLow→Operational priority:Low, unchanged from published severity.unchanged
Evidence used
No CISA KEV confirmation is currently recorded.
The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
EPSS is 0.45% for the current model date.
Compensating controls
Validate the affected product branch and deploy the verified fixed release.
Restrict the affected network interface to trusted sources where business-safe.
Monitor vendor guidance and exploitation sources for a material change.
Verification
Confirm that the asset runs Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17 and falls inside the recorded affected range.
Verify the installed build against the product-specific fixed version after deployment.
Validate exposure, authentication requirements and compensating controls in the actual environment.
Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
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-2026-66788 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitylighthouse: Dockerfile build stages use end-of-life Fedora 40 referenced by mutable tag
16 fixed
The vendor explicitly identifies these products or versions as containing the fix.
registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:329806e6d9cee8c20823f45a67c1b0cdb4a8af957c520ef8303557576e8a32f0_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:5ae6ea9d9cdeab414a4010e580455a2eb7d1dc23e62d27d1629f531d10930e8d_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:6ad357fc6bd252aad971852abf04c809245e8774b0af10b32f9f01393d7abebf_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:ecce053c0601c91638c2f9aea23289e685194839886b5d1701ccbf602d20ce75_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:321dc468744626a9542c344381f9db454d7cbc7a69e3a925365ce1d8ae8ca474_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:4b0e567a6b91e16899ad070e6ebe366885e5c2f333ed5f55cfa7e2bd8fc98565_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:7977035d3755e95121062d90a386a6b23af5d394dacb7c5e622098d70285e1d3_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:d58913107527d89b998ea945f7aa164ee8ca67de994965e7aa08dc659f4dd818_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/subctl-rhel9@sha256:1b38ba10de27535bc6e76dac4db2e66b95e7c666f20136c15d7ac11531c541df_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/subctl-rhel9@sha256:a8f500a30142993b8d07f4ed5b29007d89c6edc09ece1bbd72b4467e1a504c6b_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/subctl-rhel9@sha256:d5ff003a3893554a20712a9aebda49be7a6e83594ecc5fd8bb898567734c86b8_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
registry.redhat.io/rhacm2/subctl-rhel9@sha256:fb5fdb72a0f7d4b8555359d506eebd63d10713a2fd24b5a3669554155f620c62_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
Summary
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.
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-2026-63535
No EUVD known-exploited evidence
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
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
3.7 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled
Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available
01
What, why and how
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
What
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
Why
The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may gain additional privileges.
What
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
Why
The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may gain additional privileges.
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 → Use of Unmaintained Third Party Components → gain additional privileges
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-1104: Use of Unmaintained Third Party Components. The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.
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:H/PR:N/UI:N/S:U/C:N/I:L/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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.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.
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-63535Official EUVD mapping
A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.
Official EUVD record ↗Cyber Security Agency of Singapore · English · CSA-SB-20260826Security Bulletin 26 Aug 2026
The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 26 Aug 2026, published on 26 August 2026. Open the linked bulletin for the product, severity and reference information published in that issue.
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.
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 20 Aug 2026 · Last source change 3 Sept 2026, 04:41 UTC · CWE-1104 · Use of Unmaintained Third Party Components
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 2026-08-23
European sourceENISA EUVD · EUVD-2026-63535
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment
Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.
Affected versionsThe structured affected or fixed version information changed.
Before
See the vendor and CVE records for the affected range. · Fixed: No fixed version is explicitly recorded in the structured CVE data.
After
See the vendor and CVE records for the affected range. · Fixed: Red Hat Advanced Cluster Management for Kubernetes 2.17: 1788023916 < *, 1788023940 < *, 1788105072 < *, 1788073481 < *
Affected versionsThe structured affected or fixed version information changed.
Before
rhacm2/lighthouse-agent-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/lighthouse-coredns-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/subctl-rhel9 as a component of Red Hat Advanced Cluster Management for Kubernetes 2; rhacm2/submariner-rhel9-operator as a component of Red Hat Advanced Cluster Management for Kubernetes 2
After
Fixed: registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:329806e6d9cee8c20823f45a67c1b0cdb4a8af957c520ef8303557576e8a32f0_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:5ae6ea9d9cdeab414a4010e580455a2eb7d1dc23e62d27d1629f531d10930e8d_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:6ad357fc6bd252aad971852abf04c809245e8774b0af10b32f9f01393d7abebf_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-agent-rhel9@sha256:ecce053c0601c91638c2f9aea23289e685194839886b5d1701ccbf602d20ce75_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:321dc468744626a9542c344381f9db454d7cbc7a69e3a925365ce1d8ae8ca474_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:4b0e567a6b91e16899ad070e6ebe366885e5c2f333ed5f55cfa7e2bd8fc98565_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:7977035d3755e95121062d90a386a6b23af5d394dacb7c5e622098d70285e1d3_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/lighthouse-coredns-rhel9@sha256:d58913107527d89b998ea945f7aa164ee8ca67de994965e7aa08dc659f4dd818_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/subctl-rhel9@sha256:1b38ba10de27535bc6e76dac4db2e66b95e7c666f20136c15d7ac11531c541df_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/subctl-rhel9@sha256:a8f500a30142993b8d07f4ed5b29007d89c6edc09ece1bbd72b4467e1a504c6b_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/subctl-rhel9@sha256:d5ff003a3893554a20712a9aebda49be7a6e83594ecc5fd8bb898567734c86b8_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/subctl-rhel9@sha256:fb5fdb72a0f7d4b8555359d506eebd63d10713a2fd24b5a3669554155f620c62_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/submariner-rhel9-operator@sha256:0714135f3594b0e42c4d185779b3a716fc98c6bc35135aa6dec2c9730c93ae52_s390x as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/submariner-rhel9-operator@sha256:1c0fe9629265844d3cd36fa6fd358026087240dee118e1d438f3ac273f427054_amd64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/submariner-rhel9-operator@sha256:5d1225146756be65df394eeb2ec2afa87b025b6e5bfbc9ddd89eaff47d5a40d8_ppc64le as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17; registry.redhat.io/rhacm2/submariner-rhel9-operator@sha256:93850d48fc8efac7bc3630e4102f5471bcf84921a31c17bc1512e77a4602fc36_arm64 as a component of Red Hat Advanced Cluster Management for Kubernetes 2.17
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.