CVE-2026-45657

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-09. the CNA's CVSS baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this weekElevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 15%CVSS: 9.8Exploit: NoneExposed: 0

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

Use after free in Windows Kernel allows an unauthorized attacker to execute code over a network.

CVSS v3
9.8
EG Score
9.8(high)
EPSS
96.4%
KEV
Not listed

Published

June 9, 2026

Last Modified

July 1, 2026

Advisory Details (1)

Auto-updated Jul 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-2026-45657

Vendor Advisories for CVE-2026-45657(2)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 90× in last 7d / 433× 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 433 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-45657?
CVE-2026-45657 is a critical vulnerability published on June 9, 2026. Use after free in Windows Kernel allows an unauthorized attacker to execute code over a network.
When was CVE-2026-45657 disclosed?
CVE-2026-45657 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45657 actively exploited?
CVE-2026-45657 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 96.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45657?
CVE-2026-45657 has a CVSS v4.0 base score of 9.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-45657?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45657, 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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