Deserialization of Untrusted Data in Microsoft SharePoint Server - CVE-2026-58644
Published: July 17, 2026
Vulnerability identifier: #VU138286
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-58644
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to deserialization of untrusted data in Microsoft Office SharePoint when processing network requests. A remote attacker can send crafted serialized data to execute arbitrary code.
Exploitation has been detected in the wild.
Affected software
Microsoft SharePoint Server
How to mitigate CVE-2026-58644
Install security update from vendor's website.
Microsoft SharePoint Server - addressed in versions 16.0.5556.1005, 16.0.10417.20153, 16.0.19725.20384