CVE-2026-21509

HighCVSS 7.8/10Known exploited (CISA KEV)Last modified Jun 25, 2026

Description

Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.

Metrics

CVSS 3.1 7.8/10CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-807

Affected software

No affected versions have been published.

Timeline

Published
Jan 26, 2026
Last modified
Jun 25, 2026
Added to CISA KEV
Jan 26, 2026
NVD status
Analyzed

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CVE-2026-21509: High severity, CVSS 7.8 | Vulnix