CVE-2026-45659
Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability
CVSS
8.8
Alto
EPSS
3.2%
p87
KEV
SÍ
1 jul 2026
Exploit Today
76
0-100
Publicado: 22 may 2026 · Última mod.: 2 jul 2026 · CWE-502
Producto
Microsoft / SharePoint Server
Vulnerabilidad
Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability
Añadido a KEV
1 jul 2026
Remediar antes de
4 jul 2026
Uso conocido en ransomware
No
Descripción resumida
Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.
Acción requerida
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.
Notas
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45659 ; 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-2026-45659
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.