CVE-2026-58644

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-07-16), indicating real-world exploitation has been confirmed by US federal agencies. the CNA's CVSS baseline 9.8 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
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 16%CVSS: 9.8Exploit: 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.

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
16%
EPSS %ILE
97%
KEV
⚠ Exploited

Published

July 14, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Aug 28, 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-2026-58644
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-2026-58644

Vendor Advisories for CVE-2026-58644(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 92× in last 7d / 386× 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 4,129 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

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

  • Nucleihttp/cves/2026/CVE-2026-58644.yaml
    First seen Jan 1, 2026

    Microsoft SharePoint Server - WS-Federation BinaryFormatter Deserialization RCE

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2026-58644?
CVE-2026-58644 is a critical vulnerability published on July 14, 2026. Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
When was CVE-2026-58644 disclosed?
CVE-2026-58644 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-2026-58644 actively exploited?
Yes. CISA added CVE-2026-58644 to the Known Exploited Vulnerabilities catalog on July 16, 2026, affecting Microsoft SharePoint. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-58644?
CVE-2026-58644 has a CVSS v4.0 base score of 9.8 (CNA self-assessment; NVD's own analysis pending).
Which products are affected by CVE-2026-58644?
CVE-2026-58644 affects Microsoft SharePoint. 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-2026-58644?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58644, 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-2026-58644

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