CVE-2026-45659: Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Other sources
Microsoft SharePoint Remote Code Execution Vulnerability
— Microsoft
Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.
— CISA
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 16.0.5552.1002Patch KB5002868 - 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 16.0.19725.20280Patch KB5002863
Event History
Frequently Asked Questions
What is the severity of CVE-2026-45659?
CVE-2026-45659 has a severity rating of 8.8, which is classified as high.
How do I fix CVE-2026-45659?
To mitigate CVE-2026-45659, apply the latest security updates provided by Microsoft for the affected SharePoint versions.
What software is affected by CVE-2026-45659?
CVE-2026-45659 affects Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server Subscription Edition, and Microsoft SharePoint Server 2019.
What type of vulnerability is CVE-2026-45659?
CVE-2026-45659 is a remote code execution vulnerability caused by the deserialization of untrusted data.
Can CVE-2026-45659 be exploited remotely?
Yes, CVE-2026-45659 can be exploited remotely by an authorized attacker over a network.