CVE-2026-41091

HIGHPre-NVD 7.89.0▲
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 7.8 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
7.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 8%CVSS: 7.8Exploit: NoneExposed: 0

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

Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.

CVSS v3
7.8
EG Score
9.0(high)
EPSS
94.3%
KEV
⚠ Exploited

Published

May 20, 2026

Last Modified

June 19, 2026

Advisory Details (1)

Auto-updated May 20, 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-2026-41091

Vendor Advisories for CVE-2026-41091(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 131× in last 7d / 547× 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 816 total refreshes for this CVE.

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

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCtc4dy/CVE-2026-41091-PoC-Exploit
    First seen Jun 20, 2026

    🔥 CVE-2026-41091 SolarFlare | Microsoft Defender LPE exploit. Low-privileged users gain NT AUTHORITY\SYSTEM via Cloud Files API + NTFS junction trickery. Forces Defender to write malicious payloads to System32 with SYSTEM rights. ⚠️ Actively exploited in wild. CVSS 7.8. Patch: Defender Engine 1.1.26040.8. 🛡️ Educational PoC only.

    Open source ↗
  • GitHub PoC0xBlackash/CVE-2026-41091
    First seen May 21, 2026

    CVE-2026-41091

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2026-41091?
CVE-2026-41091 is a high vulnerability published on May 20, 2026. Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.
When was CVE-2026-41091 disclosed?
CVE-2026-41091 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-2026-41091 actively exploited?
Yes. CISA added CVE-2026-41091 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-2026-41091?
CVE-2026-41091 has a CVSS v4.0 base score of 7.8 (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-2026-41091?
CVE-2026-41091 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-2026-41091?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-41091, 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-2026-41091

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