CVE-2026-66787Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice ip addresses
- 8.7HighCVSS base score
- 0.30%Exploitation in 30 daysEPSS · top 77% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw was found in the lighthouse component of Red Hat Advanced Cluster Management for Kubernetes. This vulnerability stems from insufficient validation of advertised IP addresses within EndpointSlice objects. A compromised spoke cluster can exploit this by creating EndpointSlices with attacker-controlled IP addresses, causing other clusters' lighthouse DNS to redirect legitimate service traffic to malicious endpoints. This enables a remote attacker to conduct transparent Man-in-the-Middle (MITM) attacks on cross-cluster service communications, potentially leading to unauthorized information disclosure and data manipulation.
Timeline
ID reserved
By redhat
- 24 days later
· 24 days later
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
| NVDNVD · Awaiting Analysis | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.30% · top 77% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Affected products
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.16
- unaffected 1790670439 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.16
- unaffected 1790670231 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.16
- unaffected 1790670243 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.16
- unaffected 1790670912 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.17
- unaffected 1788023916 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.17
- unaffected 1788023940 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.17
- unaffected 1788105072 – < *
Red Hat · Red Hat Advanced Cluster Management for Kubernetes 2.17
- unaffected 1788073481 – < *
What to do
Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
References
References4
- RHSA-2026:63016 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:85227 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-66787 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2507532 (opens in a new tab)issue-trackingx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-63533 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-66787)Record last updated .