CVE-2026-50522: critical vulnerability in Microsoft SharePoint Enterprise Server 2016
Microsoft SharePoint Remote Code Execution Vulnerability
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
Prioritize patching. It under exploitation confirmed by CISA, has an official Brazilian government alert and has a public proof of concept.
Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.
- CTIR Gov · ALERTA 63/2026 · 23 Jul 2026Vulnerabilidade crítica que afeta o SharePointread on gov.br ↗
- CISC Gov.br · 21 Jul 2026Boletim do CISC de Vulnerabilidaderead on gov.br ↗
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.
Microsoft SharePoint can be tricked into running malicious code sent over the network because it doesn't properly check data before processing it. This is dangerous because attackers can take complete control of the affected system without needing special access.
The vulnerability exists in SharePoint's deserialization mechanism (CWE-502) which processes untrusted data without validation, allowing remote code execution. An attacker can send malicious serialized objects over the network to achieve code execution with no prior authentication required, resulting in complete system compromise.
In the same product, most dangerous first.