CVE-2026-45498

MEDIUMPre-NVD 4.09.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-05-20), indicating real-world exploitation has been confirmed by US federal agencies. the CNA's CVSS baseline 4.0 retained for reference (NVD's own analysis pending). Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, cna:microsoft, epss, ghsa
Trending — 5 sources updated this weekExploited in the wild
4.0
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 63%CVSS: 4.0Exploit: NoneExposed: 0

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

Microsoft Defender Denial of Service Vulnerability

CVSS v3
4.0
EG Score
9.0(high)
EPSS
99.1%
KEV
⚠ Exploited

Published

May 20, 2026

Last Modified

June 19, 2026

Advisory Details (1)

Auto-updated Jun 15, 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-2026-45498

Vendor Advisories for CVE-2026-45498(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 128× in last 7d / 550× 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 845 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2026-45498?
CVE-2026-45498 is a medium vulnerability published on May 20, 2026. Microsoft Defender Denial of Service Vulnerability
When was CVE-2026-45498 disclosed?
CVE-2026-45498 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45498 actively exploited?
Yes. CISA added CVE-2026-45498 to the Known Exploited Vulnerabilities catalog on May 20, 2026, affecting Microsoft Defender. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-45498?
CVE-2026-45498 has a CVSS v4.0 base score of 4.0 (CNA self-assessment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2026-45498?
CVE-2026-45498 affects Microsoft Defender. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2026-45498?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45498, 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-2026-45498

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