CISA Adds Actively Exploited SharePoint RCE (CVE-2026-45659) to KEV Catalog

CISA added CVE-2026-45659, a high-severity remote code execution flaw in Microsoft SharePoint Server, to its Known Exploited Vulnerabilities catalog after confirming active exploitation. The bug (CVSS 8.8) stems from deserialization of untrusted data, allowing an attacker to achieve remote code execution. Organizations running affected SharePoint Server versions should prioritize patching and review logs for signs of exploitation. Federal agencies are required to remediate KEV-listed vulnerabilities on CISA’s mandated timeline.