CVE-2026-40357: Microsoft SharePoint Server Remote Code Execution Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Other sources
Microsoft SharePoint Server Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.10417.20128Patch KB5002870 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5552.1002Patch KB5002868 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.19725.20280Patch KB5002863
Event History
Frequently Asked Questions
What is the severity of CVE-2026-40357?
CVE-2026-40357 has a critical severity rating due to its potential for remote code execution by attackers.
How do I fix CVE-2026-40357?
To mitigate CVE-2026-40357, apply the relevant security updates for your version of Microsoft SharePoint as provided by Microsoft.
What versions of SharePoint are affected by CVE-2026-40357?
CVE-2026-40357 affects Microsoft SharePoint Server 2019, SharePoint Enterprise Server 2016, and SharePoint Server Subscription Edition.
Can I exploit CVE-2026-40357 without being an authorized user?
No, the CVE-2026-40357 vulnerability requires an attacker to be an authorized user to exploit it.
Is there a known exploit for CVE-2026-40357?
As of now, there are reports of exploitation attempts targeting CVE-2026-40357 in the wild.