Actively exploited
Listed in CISA’s Known Exploited Vulnerabilities catalog since March 18, 2026.
CVE-2026-20963
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Added to KEV March 18, 2026
Alert details
- Source feed
- CISA KEV
- CVE ID
- CVE-2026-20963
- CWE
- CWE-502
- Affected products
- SharePoint · Microsoft SharePoint · Microsoft
What happened
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
What it means for your business
Microsoft SharePoint is listed in CISA's Known Exploited Vulnerabilities catalog (CVE-2026-20963). Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network. CISA remediation due date: 2026-03-21. If you need help checking exposure, call (864) 335-9223.
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: March 21, 2026
Sources
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