CVE-2026-58644

CRITICALCVSS 9.8Known Exploited

CISA Known Exploited Vulnerability

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58644 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-58644

Remediation deadline: July 19, 2026

Description

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

Timeline

Published:July 14th, 2026 5:17 PM

Last modified:July 17th, 2026 5:16 AM

Added to KEV:July 16th, 2026

CVSS Scoring

CVSS v3: 9.8 (CRITICAL)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Software

From NVD CPE configuration data

Vendors

microsoft

Products

sharepoint_server

Weaknesses (CWE)

CWE-502

References & Reports

Advisories, patches, and third-party reports

Source: NIST NVD · Data may lag official sources by up to one minute