CVE-2026-66313

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

Score 6.8 from GitHub Security Advisory published 2026-08-04. the CNA's CVSS baseline 6.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: 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 tampering locally.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
31(Track)
EG Risk 31/100SSVC: 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
Severity68% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

August 3, 2026

Last Modified

September 17, 2026

Advisory Details (1)

Auto-updated Aug 3, 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-2026-66313

Vendor Advisories for CVE-2026-66313(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 24× in last 7d / 100× 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 175 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-66313?
CVE-2026-66313 is a medium vulnerability published on August 3, 2026. Origin validation error in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.
When was CVE-2026-66313 disclosed?
CVE-2026-66313 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-2026-66313 actively exploited?
CVE-2026-66313 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 93.5% of all scored CVEs.
What is the CVSS score of CVE-2026-66313?
CVE-2026-66313 has a CVSS v4.0 base score of 6.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-66313?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66313, 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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