CVE-2026-66804

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-11. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this weekElevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 5%CVSS: 7.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
51(Track)
EG Risk 51/100SSVC: 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 computed
Severity78% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
5%
EPSS %ILE
92%
KEV
Not listed

Published

August 11, 2026

Last Modified

September 16, 2026

Advisory Details (1)

Auto-updated Aug 11, 2026
Patch available. Sources: microsoft.
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66804

Vendor Advisories for CVE-2026-66804(14)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(12)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhacm2/console-rhel9:17873392482026-08-26redhat
redhatrhacm2/console-rhel9:17876870622026-08-26redhat
redhatrhacm2/console-rhel9:17873351052026-08-26redhat
redhatrhacm2/console-rhel9:17873392492026-08-26redhat
redhatrhacm2/console-rhel9:17873417802026-08-26redhat
redhatmulticluster-engine/console-mce-rhel9:17870793592026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17866688562026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17872642502026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17872590482026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17870793642026-08-25redhat
redhatmulticluster-engine/console-mce-rhel9:17869119772026-08-19redhat
redhatrhacm2/console-rhel9:17869083612026-08-19redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 39× in last 7d / 203× 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.

Showing the most recent 100 of 325 total refreshes for this CVE.

  1. 2026-09-19 02:24 UTCEG score recompute
  2. 2026-09-19 02:24 UTCVendor advisory
  3. 2026-09-19 02:24 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 14:43 UTCVendor advisory
  6. 2026-09-18 14:43 UTCGHSA enrichment
  7. 2026-09-18 03:18 UTCEG score recompute
  8. 2026-09-18 03:18 UTCVendor advisory
  9. 2026-09-18 03:18 UTCGHSA enrichment
  10. 2026-09-17 15:53 UTCVendor advisory
  11. 2026-09-17 15:53 UTCGHSA enrichment
  12. 2026-09-17 04:28 UTCVendor advisory
  13. 2026-09-17 04:28 UTCGHSA enrichment
  14. 2026-09-16 17:03 UTCEG score recompute
  15. 2026-09-16 17:03 UTCVendor advisory
  16. 2026-09-16 17:03 UTCGHSA enrichment
  17. 2026-09-16 14:08 UTCEPSS rescore
  18. 2026-09-16 10:56 UTCEG score recompute
  19. 2026-09-16 10:56 UTCVendor advisory
  20. 2026-09-16 10:56 UTCGHSA enrichment
  21. 2026-09-16 05:15 UTCEPSS rescore
  22. 2026-09-15 22:45 UTCVendor advisory
  23. 2026-09-15 22:45 UTCGHSA enrichment
  24. 2026-09-15 06:28 UTCEG score recompute
  25. 2026-09-15 06:28 UTCVendor advisory
Show 75 more
  1. 2026-09-15 06:28 UTCGHSA enrichment
  2. 2026-09-14 18:01 UTCVendor advisory
  3. 2026-09-14 18:01 UTCGHSA enrichment
  4. 2026-09-14 13:57 UTCVendor advisory
  5. 2026-09-14 13:57 UTCGHSA enrichment
  6. 2026-09-14 02:24 UTCVendor advisory
  7. 2026-09-14 02:24 UTCGHSA enrichment
  8. 2026-09-13 14:59 UTCVendor advisory
  9. 2026-09-13 14:59 UTCGHSA enrichment
  10. 2026-09-13 03:32 UTCVendor advisory
  11. 2026-09-13 03:32 UTCGHSA enrichment
  12. 2026-09-12 16:07 UTCEG score recompute
  13. 2026-09-12 16:07 UTCVendor advisory
  14. 2026-09-12 16:07 UTCGHSA enrichment
  15. 2026-09-12 04:42 UTCVendor advisory
  16. 2026-09-12 04:42 UTCGHSA enrichment
  17. 2026-09-11 17:17 UTCVendor advisory
  18. 2026-09-11 17:17 UTCGHSA enrichment
  19. 2026-09-11 16:01 UTCVendor advisory
  20. 2026-09-11 16:01 UTCGHSA enrichment
  21. 2026-09-11 15:38 UTCVendor advisory
  22. 2026-09-11 15:38 UTCGHSA enrichment
  23. 2026-09-11 14:56 UTCEG score recompute
  24. 2026-09-11 14:56 UTCVendor advisory
  25. 2026-09-11 14:56 UTCGHSA enrichment
  26. 2026-09-11 14:53 UTCEPSS rescore
  27. 2026-09-11 09:37 UTCEPSS rescore
  28. 2026-09-11 03:31 UTCEG score recompute
  29. 2026-09-11 03:31 UTCVendor advisory
  30. 2026-09-11 03:31 UTCGHSA enrichment
  31. 2026-09-10 16:06 UTCEG score recompute
  32. 2026-09-10 16:06 UTCVendor advisory
  33. 2026-09-10 16:06 UTCGHSA enrichment
  34. 2026-09-10 08:41 UTCVendor advisory
  35. 2026-09-10 08:41 UTCGHSA enrichment
  36. 2026-09-09 20:54 UTCVendor advisory
  37. 2026-09-09 20:54 UTCGHSA enrichment
  38. 2026-09-09 09:37 UTCVendor advisory
  39. 2026-09-09 09:37 UTCGHSA enrichment
  40. 2026-09-08 22:12 UTCEG score recompute
  41. 2026-09-08 22:12 UTCVendor advisory
  42. 2026-09-08 22:12 UTCGHSA enrichment
  43. 2026-09-08 22:01 UTCEPSS rescore
  44. 2026-09-08 18:24 UTCVendor advisory
  45. 2026-09-08 18:24 UTCGHSA enrichment
  46. 2026-09-08 04:26 UTCVendor advisory
  47. 2026-09-08 04:26 UTCGHSA enrichment
  48. 2026-09-07 16:51 UTCEG score recompute
  49. 2026-09-07 16:51 UTCVendor advisory
  50. 2026-09-07 16:51 UTCGHSA enrichment
  51. 2026-09-07 16:01 UTCEPSS rescore
  52. 2026-09-06 23:22 UTCEG score recompute
  53. 2026-09-06 23:22 UTCVendor advisory
  54. 2026-09-06 23:22 UTCGHSA enrichment
  55. 2026-09-06 13:47 UTCEPSS rescore
  56. 2026-09-06 11:56 UTCVendor advisory
  57. 2026-09-06 11:56 UTCGHSA enrichment
  58. 2026-09-06 00:31 UTCEG score recompute
  59. 2026-09-06 00:31 UTCVendor advisory
  60. 2026-09-06 00:31 UTCGHSA enrichment
  61. 2026-09-05 15:31 UTCEPSS rescore
  62. 2026-09-05 13:06 UTCVendor advisory
  63. 2026-09-05 13:06 UTCGHSA enrichment
  64. 2026-09-05 01:32 UTCEG score recompute
  65. 2026-09-05 01:32 UTCVendor advisory
  66. 2026-09-05 01:32 UTCGHSA enrichment
  67. 2026-09-04 09:11 UTCEG score recompute
  68. 2026-09-04 09:11 UTCVendor advisory
  69. 2026-09-04 09:11 UTCGHSA enrichment
  70. 2026-09-04 05:07 UTCEPSS rescore
  71. 2026-09-03 21:45 UTCVendor advisory
  72. 2026-09-03 21:44 UTCGHSA enrichment
  73. 2026-09-03 15:42 UTCVendor advisory
  74. 2026-09-03 15:42 UTCGHSA enrichment
  75. 2026-09-03 07:01 UTCVendor advisory

Publicly available exploits

(3 references)

Working exploit code is in the public domain (3 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCRat5ak/CVE-2026-66804-CrossDevice-Service-EoP
    First seen Aug 13, 2026

    CVE-2026-66804 Windows Cross Device virtual camera EoP

    Open source ↗
  • GitHub PoCDavidCarliez/CVE-2026-66804-CrossDevice-LPE
    First seen Jul 23, 2026
    Open source ↗
  • GitHub PoCZeroDayVPN/CVE-2026-66804-CrossDevice-Service-EoP
    First seen Jul 19, 2026

    sadsadsa

    Open source ↗

Frequently asked(5)

What is CVE-2026-66804?
CVE-2026-66804 is a high vulnerability published on August 11, 2026. Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.
When was CVE-2026-66804 disclosed?
CVE-2026-66804 was first published in the National Vulnerability Database on August 11, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66804 actively exploited?
CVE-2026-66804 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5% probability of exploitation in the next 30 days, which ranks it in the top 7.8% of all scored CVEs.
What is the CVSS score of CVE-2026-66804?
CVE-2026-66804 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-66804?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66804, 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-2026-66804

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