CISA Known Exploited Vulnerability

CVE-2026-21509

Microsoft · Office

Microsoft Office Security Feature Bypass Vulnerability

Date added
BOD 22-01 due date
CWE CWE-807
Ransomware Unknown

CISA description

Microsoft Office contains a security feature bypass vulnerability in which reliance on untrusted inputs in a security decision in Microsoft Office could allow an unauthorized attacker to bypass a security feature locally. Some of the impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version.

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Notes & references