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

September 17, 2026

Advisory Details (2)

Auto-updated Sep 17, 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 93× 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 4,411 total refreshes for this CVE.

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

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 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 September 17, 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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