CVE-2026-56164

CRITICALPre-NVD 5.39.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-07-14), indicating real-world exploitation has been confirmed by US federal agencies. the CNA's CVSS baseline 5.3 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
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 27%CVSS: 5.3Exploit: cisa kev · ssvc active · epss top5pct · public exploitExposed: 0

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

Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.

CVSS v3
5.3
EG Score
9.0(high)
EG Risk
96(Attend)
EG Risk 96/100SSVC: 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%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
27%
EPSS %ILE
98%
KEV
⚠ Exploited

Published

July 14, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Jul 14, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa, microsoft.
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-2026-56164
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-2026-56164

Vendor Advisories for CVE-2026-56164(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 103× in last 7d / 421× 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 5,587 total refreshes for this CVE.

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

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 PoCsam00/POC-CVE-2026-56164-exploit
    First seen Aug 6, 2026

    CVE-2026-56164 is a critical missing-authentication vulnerability affecting on-premises Microsoft SharePoint Server. It allows unauthenticated, remote attackers to elevate privileges over a network.

    Open source ↗
  • GitHub PoCsentinel-aidefense/CVE-2026-56164-EXP
    First seen Jul 15, 2026

    CVE-2026-56164 EOP Exploit

    Open source ↗

Frequently asked(6)

What is CVE-2026-56164?
CVE-2026-56164 is a critical vulnerability published on July 14, 2026. Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
When was CVE-2026-56164 disclosed?
CVE-2026-56164 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56164 actively exploited?
Yes. CISA added CVE-2026-56164 to the Known Exploited Vulnerabilities catalog on July 14, 2026, affecting Microsoft SharePoint Server. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-56164?
CVE-2026-56164 has a CVSS v4.0 base score of 5.3 (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-2026-56164?
CVE-2026-56164 affects Microsoft SharePoint Server. 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-2026-56164?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56164, 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-2026-56164

Explore →

Is Your Infrastructure Affected by CVE-2026-56164?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs