CVE-2026-45638

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-09. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

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

Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
20.9%
KEV
Not listed

Published

June 9, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jun 9, 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-2026-45638

Vendor Advisories for CVE-2026-45638(2)

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.

Data Freshness Timeline

(refreshed 9× in last 7d / 95× 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 173 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-45638?
CVE-2026-45638 is a high vulnerability published on June 9, 2026. Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
When was CVE-2026-45638 disclosed?
CVE-2026-45638 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45638 actively exploited?
CVE-2026-45638 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45638?
CVE-2026-45638 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-45638?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45638, 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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