Critical SharePoint RCE CVE-2026-50522 Under Active Exploitation After Public PoC

A critical vulnerability in Microsoft Office SharePoint, identified as CVE-2026-50522, is being actively exploited. This flaw, which has a CVSS score of 9.8, allows an unauthorized attacker to execute code over a network due to deserialization of untrusted data. The vulnerability was patched by Microsoft in its July 2026 Patch Tuesday update. Microsoft credited DEVCORE for discovering the issue. The active exploitation follows the public release of a proof-of-concept for the vulnerability.