THE Known Exploited Vulnerabilities Catalog lists CVE-2026-20963, a Microsoft SharePoint Deserialization of Untrusted Data Vulnerability that could allow an unauthorised attacker to execute code over a network. The entry notes related CWE-502 and states that the vulnerability is currently Unknown in terms of being used in ransomware campaigns. Date Added is 2026-03-18 and the Due Date is 2026-03-21.
Action recommended is to apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Additional references include the MSRC vulnerability page and the NVD entry for CVE-2026-20963. According to the Known Exploited Vulnerabilities Catalog, organisations should use these mitigations as part of vulnerability management prioritisation to better defend networks.