CVE-2026-58644

CRITICAL

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

CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 7/14/2026Modified: 7/17/2026

Related Intelligence (5)

CRITICALMalware

CVE-2026-58644: Microsoft SharePoint Server Unauthenticated Remote Code Execution Vulnerability Exploited in the Wild

Overview On July 14, 2026, Microsoft published a security advisory addressing CVE-2026-58644 , a critical remote code execution (RCE) vulnerability affecting on-premises Microsoft SharePoint Server deployments. The vulnerability, which carries a CVSS v3.1 score of 9.8 (Critical), results from the deserialization of untrusted data ( CWE-502 ) and allows an unauthenticated attacker to execute arbitr

CVE-2026-58644
Rapid7
CRITICALZero Day

CISA Adds Exploited SharePoint RCE Zero-Day CVE-2026-58644 to KEV

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday added a newly patched security flaw impacting Microsoft SharePoint Server to its Known Exploited Vulnerabilities (KEV) catalog, requiring Federal Civilian Executive Branch (FCEB) agencies to apply the fixes by July 19, 2026. The vulnerability in question is CVE-2026-58644 (CVSS score: 9.8), a critical deserialization

CVE-2026-58644
The Hacker News
HIGHVulnerability

CISA KEV: Microsoft SharePoint — Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.

CVE-2026-58644Microsoft SharePoint
CISA KEV
CRITICALZero Day

Patch Tuesday - July 2026

Microsoft is publishing 622 vulnerabilities on July 2026 Patch Tuesday , including a record-breaking 416 Windows vulnerabilities. Microsoft is aware of exploitation in the wild for two of the vulnerabilities published today, both of which are listed on CISA KEV, as well as public disclosure for one other. As usual, browser vulns are not included in the Patch Tuesday count above. Rapid7 noted last

CVE-2026-55040CVE-2026-56164
Rapid7
CRITICALVulnerability

NVD CRITICAL: CVE-2026-58644 — Deserialization of untrusted data in Microsoft Office SharePoint allows an unaut...

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

CVE-2026-58644
NIST NVD

References (2)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58644PatchVendor Advisoryhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-58644US Government Resource