CVE-2026-20963
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Published Jan 13, 2026 · updated Jun 17, 2026 · Microsoft SharePoint
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Timeline
Detection, updates, and resolution for this record.
Jan 13, 2026 · Catalog
Detected
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Mar 18, 2026 · CISA KEV
Known exploited
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Mar 21, 2026 · CISA KEV
Remediation due
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Jun 17, 2026 · Catalog
Updated
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date Mar 21, 2026
Affected
- cpe microsoft/sharepoint serverversion unspecified
- cpe microsoft/sharepoint server2016
- cpe microsoft/sharepoint server2019
- vendor Microsoft SharePointversion unspecified
Sources
- CISA KEVCVE-2026-20963
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
cisa.gov - CVE.orgCVE-2026-20963
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-20963
30-day exploitation probability 29.2%
first.org - NIST NVDCVE-2026-20963
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
nvd.nist.gov