CISA
CISA Adds CVE-2026-20963 to Known Exploited Vulnerabilities Catalogue
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.
Story timeline CVE-2026-20963
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| Published (UTC) | Outlet | Headline |
|---|---|---|
| Wed 18 Mar · 21:48 UTC | Security Affairs | U.S. CISA adds Microsoft SharePoint and Zimbra flaws to its Known Exploited Vulnerabilities catalog |
| Thu 19 Mar · 00:42 UTC | CISA | CISA Adds CVE-2026-20963 to Known Exploited Vulnerabilities Catalogue |
| Thu 19 Mar · 02:38 UTC | CISA | CISA Adds CVE-2026-20963 to Known Exploited Vulnerabilities Catalogue (this article) |
| Thu 19 Mar · 06:56 UTC | The Hacker News | CISA Warns of Zimbra, SharePoint Flaw Exploits; Cisco Zero-Day Hit in Ransomware Attacks |
| Thu 19 Mar · 09:59 UTC | SecurityWeek | CISA Warns of Attacks Exploiting Recent SharePoint Vulnerability |