CVE-2026-21510

HIGHNVD 8.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-02-10), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
8.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 26%CVSS: 8.8Exploit: NoneExposed: 0

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

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

CVSS v3
8.8
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
97.8%
KEV
⚠ Exploited

Published

February 10, 2026

Last Modified

February 11, 2026

Advisory Details (2)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: microsoft, cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21510
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-2026-21510

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 94× in last 7d / 402× 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 714 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCEpSiLoNPoInTOrI/EpSiLoNPoInTlnk
    First seen May 9, 2026

    CVE-2026-21510 LNK generator PoC

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2026-21510?
CVE-2026-21510 is a high vulnerability published on February 10, 2026. Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.
When was CVE-2026-21510 disclosed?
CVE-2026-21510 was first published in the National Vulnerability Database on February 10, 2026, with the most recent update on February 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21510 actively exploited?
Yes. CISA added CVE-2026-21510 to the Known Exploited Vulnerabilities catalog on February 10, 2026, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-21510?
CVE-2026-21510 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2026-21510?
CVE-2026-21510 affects Microsoft Windows. 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-2026-21510?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21510, 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-2026-21510

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