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Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

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Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Security researchers disclosed an AI-assisted exploit chain against Microsoft SharePoint that achieves unauthenticated remote code execution by impersonating any user, including administrators. The vulnerability, CVE-2026-55040 with a CVSS score of 9.1, impacts SharePoint Server Subscription Edition, 2019, and 2016. AI agents played a significant role in discovering the vulnerability chain.

Why it matters: SharePoint administrators and organizations running affected versions face immediate risk of complete server compromise without authentication; patching or disabling the affected functionality should be prioritized.

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Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

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Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Researchers disclosed CVE-2026-55040, a critical vulnerability in Microsoft SharePoint Server affecting multiple versions that permits unauthenticated attackers to assume administrative access. The discovery involved artificial intelligence (AI) agents in the exploit chain research. Microsoft patched the flaw, which carried a CVSS score of 9.1.

Why it matters: Organizations running SharePoint Server 2016, 2019, or Subscription Edition must apply Microsoft's patch immediately to prevent unauthorized administrative access and remote code execution from untrusted networks.

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Correction

Correction recorded as of .

vulnerabilities

Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Researchers disclosed CVE-2026-55040, a critical vulnerability in Microsoft SharePoint Server affecting multiple versions that permits unauthenticated attackers to assume administrative access. The discovery involved artificial intelligence (AI) agents in the exploit chain research. Microsoft patched the flaw, which carried a CVSS score of 9.1.

Why it matters: Organizations running SharePoint Server 2016, 2019, or Subscription Edition must apply Microsoft's patch immediately to prevent unauthorized administrative access and remote code execution from untrusted networks.

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