$ cve CVE-2026-58644 JSON

CVE-2026-58644 KEV

9.8

CRITICAL · CVSS 3.1 · EPSS 15.9% (pctl 97)

Patch first

On CISA KEV — known exploited in the wild, due 2026-07-19.

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

CVSS	9.8 (CRITICAL, v3.1)
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS	15.87% — more likely to be exploited than 97% of all CVEs
Weakness	CWE-502
On CISA KEV	yes — remediate by 2026-07-19
Public exploit	none known
Published	2026-07-14
Last modified	2026-07-17

Name	Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Added	2026-07-16
Due	2026-07-19
Vendor / product	Microsoft / SharePoint
Ransomware use	none reported

Vendor	Product
microsoft	sharepoint server