SharePoint RCE CVE-2026-45659 Added to CISA KEV After Active Exploitation
Jul 02, 2026
Vulnerability / Threat Intelligence
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Wednesday added a high-severity flaw impacting Microsoft SharePoint Server to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence of active exploitation. The vulnerability, tracked as CVE-2026-45659 (CVSS score: 8.8), is a case of remote code execution arising from the deserialization of untrusted data. The issue was addressed by Microsoft in May 2026 for SharePoint Server Subscription Edition, SharePoint Server 2019, and SharePoint Enterprise Server 2016. Microsoft noted that any authenticated attacker could trigger the vulnerability, and that it does not require admin or other elevated privileges. In a network-based attack, an authenticated attacker with a minimum of Site Member permissions (PR:L) could leverage it to execute code remotely on the SharePoint Server. "Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker t...
