Microsoft Office Vulnerability CVE-2026-21509 Under Active Exploitation

First seen 27 Jan 2026, 22:53 UTC • Sophos

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A critical vulnerability (CVE-2026-21509) in Microsoft Office has been identified, allowing attackers to exploit the application's reliance on untrusted inputs for security decisions. This flaw enables the bypassing of Object Linking and Embedding (OLE) protections, potentially affecting numerous users. Immediate action is recommended to mitigate risks associated with this vulnerability.

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Microsoft Office Vulnerability CVE-2026-21509 Under Active Exploitation

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