Urgent Alert: CVE-2026-20963 Vulnerability on Microsoft SharePoint Actively Exploited

Thanh Hoang
Mar 20
2 min read

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added vulnerability CVE-2026-20963, related to Microsoft SharePoint, to its Known Exploited Vulnerabilities (KEV) catalog.

This is a critical Remote Code Execution (RCE) flaw that allows attackers to gain full control of enterprise server systems without requiring complex user interaction. Organizations in Vietnam utilizing SharePoint as an internal storage platform must immediately conduct security reviews and apply patches to prevent the risk of sensitive data leaks.

1. Technical Analysis of Vulnerability CVE-2026-20963

CVE-2026-20963 is identified as a critical flaw lying in the way Microsoft SharePoint handles objects in memory.

Vulnerability Type: Remote Code Execution (RCE).
Exploitation Mechanism: Attackers send specially crafted packets to an affected SharePoint server. If successful, the attacker can run arbitrary commands with the privileges of the SharePoint service account, leading to the complete compromise of the enterprise's Active Directory infrastructure.
Severity: Rated as High/Critical due to its remote exploitability and wide-ranging impact on data integrity.

2. CISA Warns of Rising Attacks on SharePoint and Zimbra

According to the latest reports from The Hacker News and Security Week, collaborative platforms like Zimbra are also being targeted by organized Advanced Persistent Threat (APT) groups, alongside SharePoint.

CVE-2026-20963 collaborative platforms like Zimbra are also being targeted by organized Advanced Persistent Threat (APT) groups, alongside SharePoint. — *Collaborative platforms like Zimbra are also being targeted by organized Advanced Persistent Threat (APT) groups, alongside SharePoint.*

CISA's addition of this vulnerability to the KEV list is a "red flag." Real-world attacks have already been recorded, where hackers exploit delays in system administrators' patching schedules to install backdoors and deploy ransomware.

Expert Note: In Vietnam, many enterprises still maintain legacy On-premise SharePoint versions without regularly checking for Microsoft security notifications, creating favorable conditions for the CVE-2026-20963 vulnerability to "invite" hackers.

3. Potential Impact on Vietnamese Enterprises

If left unaddressed, this vulnerability can cause immeasurable damage:

Strategic Data Loss: Entire bidding documents, personnel charts, and customer data hosted on SharePoint could be stolen.
Operational Disruption: Systems paralyzed due to hackers seizing control.
Reputational Damage: Enterprises face legal issues and a loss of trust from partners when information is leaked.

4. Mitigation and Prevention Solutions from IPSIP Experts

To ensure absolute safety against the CVE-2026-20963 exploit, organizations must immediately implement the following three-step roadmap:

Step 1: Emergency Patch Update

Access the Microsoft Update Center to download and install the latest patch for the SharePoint Server versions in use. This is the prerequisite and most critical measure.

Step 2: System Vulnerability Assessment (Pentest)

Utilize IPSIP's in-depth Cybersecurity Assessment service to determine if the system has already been compromised through this vulnerability. Reviewing Indicators of Compromise (IoCs) will help eliminate any latent malware "seeds."

Step 3: Implement 24/7 SOC Monitoring

The SharePoint system needs continuous monitoring to detect unusual packet transmission behavior. IPSIP provides a Security Operations Center (SOC) solution that gives instant alerts on attempts to exploit new vulnerabilities.

24/7 Managed SOC Services | Security Operations Center | IPSIP Vietnam

Vulnerability CVE-2026-20963 is no longer a theoretical risk but has become a practical weapon for hackers. Vietnamese enterprises need to proactively shift their mindset from "reactive" to "preventive" to protect their digital assets.

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