CVE-2026-58644

Analyzed
Published: 14 Jul 2026, 17:05
Last modified:20 Aug 2026, 17:01

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
45.48% HIGH
45% probability 0.00%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

14 Jul 2026, 17:05
Published
Vulnerability first disclosed
16 Jul 2026, 00:00
Added to CISA KEV
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
19 Jul 2026, 00:00
CISA Remediation Due
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
20 Aug 2026, 17:01
Last Modified
Vulnerability information updated

Description

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

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 45.48%• Percentile: 99%

Techniques & Countermeasures

  • CWE-502•Deserialization of Untrusted Data

    The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Systems

  • microsoft•microsoft sharepoint enterprise server 2016

    ≥ 16.0.0, < 16.0.5556.1005

  • microsoft•microsoft sharepoint server 2019

    ≥ 16.0.0, < 16.0.10417.20153

  • microsoft•microsoft sharepoint server subscription edition

    ≥ 16.0.0, < 16.0.19725.20384

  • microsoft•sharepoint_server

    < 16.0.19725.20434 | 2016 | 2019

References (2)