CVE-2026-102862

Summary

Microsoft SharePoint Server contains an authorization flaw that allows an authenticated user to escalate their privileges across the network, potentially leading to full system compromise. This vulnerability is particularly concerning because it can be exploited remotely without user interaction.

Exploitability

Exploitation requires an authenticated attacker with existing access to SharePoint, but is relatively straightforward since it involves leveraging incorrect authorization checks to gain elevated privileges.

Blast radius

If exploited, this flaw could allow attackers to gain administrative access across the SharePoint environment, potentially leading to data exfiltration, lateral movement, and complete system compromise.

Detection

Monitor for unusual privilege escalation events in SharePoint audit logs, particularly when authenticated users perform actions that should require higher privileges. Look for failed authentication attempts followed by successful elevated access requests.

Prioritized remediation

Apply the Microsoft security update KB5042378 for SharePoint Server 2019 or upgrade to SharePoint Server 2021 with the latest cumulative update.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.