CVE-2026-66316

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

Score 5.4 from GitHub Security Advisory published 2026-08-04. the CNA's CVSS baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

CVSS v3
5.4
EG Score
5.4(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

August 3, 2026

Last Modified

September 17, 2026

Advisory Details (1)

Auto-updated Aug 4, 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-2026-66316

Vendor Advisories for CVE-2026-66316(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.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 20× in last 7d / 106× 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 184 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-66316?
CVE-2026-66316 is a medium vulnerability published on August 3, 2026. Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.
When was CVE-2026-66316 disclosed?
CVE-2026-66316 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66316 actively exploited?
CVE-2026-66316 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 96.0% of all scored CVEs.
What is the CVSS score of CVE-2026-66316?
CVE-2026-66316 has a CVSS v4.0 base score of 5.4 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-66316?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66316, 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

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