U.S. CISA adds Microsoft SharePoint Server, and Microsoft Office Excel flaws to its Known Exploited Vulnerabilities catalog

CISA has added two Microsoft vulnerabilities to its Known Exploited Vulnerabilities catalog: CVE-2009-0238 (a high-severity Excel remote code execution previously exploited in 2009) and CVE-2026-32201 (a SharePoint spoofing/likely XSS zero-day reported as actively exploited). The advisory urges organizations and federal agencies to prioritize testing and patching—CISA requires federal remediation by April 28, 2026.