Critical severity · published Jan 13, 2026
CVE-2026-20963
Microsoft SharePoint Remote Code Execution Vulnerability
In wildKEV
9.8
CVSS
29.2%
EPSS
Yes
On KEV
Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)29.2% · higher than 98% of CVEs
Exploited in the wildYes
CISA KEVListed Mar 18, 2026
Federal remediation dueMar 21, 2026
Ransomware campaign useNot known
Affected products
Which versions
SH
SharePoint · Microsoft
before 16.0.19127.20442; 2016; 2019 · source: NVD, KEV
MS
Microsoft SharePoint Enterprise Server 2016 · Microsoft
16.0.0 before 16.0.5535.1001 · source: vendor
MS
Microsoft SharePoint Server 2019 · Microsoft
16.0.0 before 16.0.10417.20083 · source: vendor
MS
Microsoft SharePoint Server Subscription Edition · Microsoft
16.0.0 before 16.0.19127.20442 · source: vendor
In the news
VulnerabilityHigh
CISA Adds One Known Exploited Vulnerability to Catalog
CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-20963 Microsoft SharePoint Deserialization of Untrusted Data Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information. Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria . 
Mar 18, 2026·CISA Advisories
VulnerabilityCritical
[CISA KEV] CVE-2026-20963: Microsoft SharePoint - Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
SHSharePointCVE-2026-20963
Mar 18, 2026·CISA KEV
Affected product
SH
SharePoint
Microsoft
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