CVE-2026-66311

MEDIUMPre-NVD 6.26.2—
EchelonGraph scoreHIGH confidence

Score 6.2 from GitHub Security Advisory published 2026-08-04. the CNA's CVSS baseline 6.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.2Exploit: None knownExposed: 0

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

Missing authorization in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.

CVSS v3
6.2
EG Score
6.2(high)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity62% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 20, 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-2026-66311

Vendor Advisories for CVE-2026-66311(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 41× in last 7d / 89× 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.

  1. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-20 17:17 UTCVendor advisory
  3. 2026-08-20 17:17 UTCGHSA enrichment
  4. 2026-08-20 15:08 UTCEG score recompute
  5. 2026-08-20 15:08 UTCVendor advisory
  6. 2026-08-20 15:08 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 16:57 UTCVendor advisory
  9. 2026-08-19 16:57 UTCGHSA enrichment
  10. 2026-08-19 16:03 UTCVendor advisory
  11. 2026-08-19 16:03 UTCGHSA enrichment
  12. 2026-08-19 15:39 UTCVendor advisory
  13. 2026-08-19 15:39 UTCGHSA enrichment
  14. 2026-08-18 17:33 UTCVendor advisory
  15. 2026-08-18 17:33 UTCGHSA enrichment
  16. 2026-08-18 16:14 UTCEG score recompute
  17. 2026-08-18 16:14 UTCVendor advisory
  18. 2026-08-18 16:14 UTCGHSA enrichment
  19. 2026-08-18 13:48 UTCEPSS rescore
  20. 2026-08-17 18:24 UTCEG score recompute
  21. 2026-08-17 18:24 UTCVendor advisory
  22. 2026-08-17 18:24 UTCGHSA enrichment
  23. 2026-08-17 13:47 UTCEPSS rescore
  24. 2026-08-17 11:54 UTCEG score recompute
  25. 2026-08-17 11:54 UTCVendor advisory
Show 64 more
  1. 2026-08-17 11:54 UTCGHSA enrichment
  2. 2026-08-16 14:56 UTCEPSS rescore
  3. 2026-08-16 13:48 UTCEG score recompute
  4. 2026-08-16 13:48 UTCVendor advisory
  5. 2026-08-16 13:48 UTCGHSA enrichment
  6. 2026-08-15 15:42 UTCEG score recompute
  7. 2026-08-15 15:42 UTCVendor advisory
  8. 2026-08-15 15:42 UTCGHSA enrichment
  9. 2026-08-15 01:30 UTCEPSS rescore
  10. 2026-08-14 17:36 UTCVendor advisory
  11. 2026-08-14 17:36 UTCGHSA enrichment
  12. 2026-08-14 17:11 UTCVendor advisory
  13. 2026-08-14 17:11 UTCGHSA enrichment
  14. 2026-08-14 10:01 UTCEG score recompute
  15. 2026-08-14 10:01 UTCVendor advisory
  16. 2026-08-14 10:01 UTCGHSA enrichment
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-13 11:54 UTCEG score recompute
  19. 2026-08-13 11:54 UTCVendor advisory
  20. 2026-08-13 11:54 UTCGHSA enrichment
  21. 2026-08-12 13:51 UTCEPSS rescore
  22. 2026-08-12 13:48 UTCVendor advisory
  23. 2026-08-12 13:48 UTCGHSA enrichment
  24. 2026-08-11 15:41 UTCEG score recompute
  25. 2026-08-11 15:41 UTCVendor advisory
  26. 2026-08-11 15:41 UTCGHSA enrichment
  27. 2026-08-11 00:00 UTCEPSS rescore
  28. 2026-08-10 17:35 UTCGHSA enrichment
  29. 2026-08-10 12:48 UTCGHSA enrichment
  30. 2026-08-09 14:42 UTCEG score recompute
  31. 2026-08-09 14:42 UTCGHSA enrichment
  32. 2026-08-09 13:47 UTCEPSS rescore
  33. 2026-08-08 16:37 UTCEPSS rescore
  34. 2026-08-08 16:36 UTCVendor advisory
  35. 2026-08-08 16:36 UTCGHSA enrichment
  36. 2026-08-07 18:29 UTCEG score recompute
  37. 2026-08-07 18:29 UTCGHSA enrichment
  38. 2026-08-06 22:25 UTCEG score recompute
  39. 2026-08-06 22:25 UTCVendor advisory
  40. 2026-08-06 22:25 UTCGHSA enrichment
  41. 2026-08-06 17:00 UTCVendor advisory
  42. 2026-08-06 17:00 UTCGHSA enrichment
  43. 2026-08-06 15:50 UTCEG score recompute
  44. 2026-08-06 15:50 UTCVendor advisory
  45. 2026-08-06 15:50 UTCGHSA enrichment
  46. 2026-08-06 13:47 UTCEPSS rescore
  47. 2026-08-06 12:47 UTCEG score recompute
  48. 2026-08-06 12:47 UTCVendor advisory
  49. 2026-08-06 12:47 UTCGHSA enrichment
  50. 2026-08-05 19:17 UTCEPSS rescore
  51. 2026-08-05 19:17 UTCEPSS rescore
  52. 2026-08-05 14:40 UTCVendor advisory
  53. 2026-08-05 14:40 UTCGHSA enrichment
  54. 2026-08-04 16:34 UTCEG score recompute
  55. 2026-08-04 16:34 UTCVendor advisory
  56. 2026-08-04 16:34 UTCGHSA enrichment
  57. 2026-08-04 15:38 UTCEG score recompute
  58. 2026-08-04 15:38 UTCVendor advisory
  59. 2026-08-04 15:38 UTCGHSA enrichment
  60. 2026-08-04 15:10 UTCEPSS rescore
  61. 2026-08-04 00:25 UTCEG score recompute
  62. 2026-08-04 00:25 UTCVendor advisory
  63. 2026-08-03 23:20 UTCEG score recompute
  64. 2026-08-03 23:19 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66311?
CVE-2026-66311 is a medium vulnerability published on August 3, 2026. Missing authorization in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform tampering locally.
When was CVE-2026-66311 disclosed?
CVE-2026-66311 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66311 actively exploited?
CVE-2026-66311 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 66.0% of all scored CVEs.
What is the CVSS score of CVE-2026-66311?
CVE-2026-66311 has a CVSS v4.0 base score of 6.2 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-66311?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66311, 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-2026-66311

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