A flaw was found in Submariner. This vulnerability allows a malicious cluster (spoke) to redirect network traffic from other connected clusters (peer clusters) by publishing a specially crafted network endpoint. The system fails to properly validate the network subnets provided by the malicious cluster, enabling it to declare arbitrary network ranges. Consequently, all network traffic intended for these arbitrary ranges from peer clusters will be rerouted through the attacker's tunnel, potentially leading to unauthorized information disclosure or network disruption.
CVE-2026-66785
CRITICALPre-NVD 9.99.9—Trending — 3 sources updated this week
EchelonGraph scoreHIGH confidence
Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-20. a secondary CVSS source baseline 9.9; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.9Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.9
- EG Score
- 9.9(high)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity99% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
August 20, 2026
Last Modified
August 20, 2026
Advisory Details (2)
Auto-updated Aug 20, 2026Patch available. Sources: redhat.
redhat
2507530 – (CVE-2026-66785) CVE-2026-66785 submariner: submariner: unvalidated Endpoint.Spec.Subnets propagated into WireGuard AllowedIPs / IPsec enables traffic hijack
https://bugzilla.redhat.com/show_bug.cgi?id=2507530redhat Patch Available
CVE-2026-66785 - Red Hat Customer Portal
Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a
https://access.redhat.com/security/cve/CVE-2026-66785Vendor Advisories for CVE-2026-66785(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-20 23:12 UTCEG score recompute
- 2026-08-20 23:12 UTCGHSA enrichment
- 2026-08-20 19:18 UTCEG score recompute
- 2026-08-20 18:22 UTCEG score recompute
- 2026-08-20 18:21 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-66785?
CVE-2026-66785 is a critical vulnerability published on August 20, 2026. A flaw was found in Submariner. This vulnerability allows a malicious cluster (spoke) to redirect network traffic from other connected clusters (peer clusters) by publishing a specially crafted network endpoint. The system fails to properly validate the network subnets provided by the malicious…
When was CVE-2026-66785 disclosed?
CVE-2026-66785 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-66785?
CVE-2026-66785 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-66785?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66785, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-66785
Is Your Infrastructure Affected by CVE-2026-66785?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.