CVE record
CVE-2026-21509
Microsoft Office Security Feature Bypass Vulnerability
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.
CVE evidence
Known exploitation
Listed in CISA KEV
Absence from the fetched catalog does not establish that exploitation has not occurred.
Severity
unknown
No parseable CVSS vector returned
Affected packages
0
Supported package records returned by OSV. Vendor and product names are not used to infer matches.
CISA Known Exploited Vulnerabilities
Catalog record
- Vendor / project
- Microsoft
- Product
- Office
- Date added
- Jan 26, 2026
- CISA federal remediation due date
- Feb 16, 2026
- 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.
- Known ransomware campaign use
- Unknown
- CWE
- CWE-807
OSV package mapping