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)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
94.4%
KEV
⚠ Exploited

Published

May 20, 2026

Last Modified

July 24, 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 77× in last 7d / 374× 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 706 total refreshes for this CVE.

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

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 July 24, 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 v3 base score of 7.8 (NVD). 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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