Microsoft—Microsoft issued emergency patches for Office zero-day vulnerability exploited in wild attacks
Microsoft issued out-of-band security patches for a high-severity Microsoft Office zero-day vulnerability tracked as CVE-2026-21509, with a CVSS score of 7.8 out of 10.0. The vulnerability allows attackers to bypass document security checks and is being actively exploited in the wild via malicious files. The emergency patch was released outside Microsoft's normal Patch Tuesday schedule due to active exploitation.
Scoring Impact
| Topic | Direction | Relevance | Contribution |
|---|---|---|---|
| Data Security | -against | primary | -1.00 |
| User Privacy | -against | secondary | -0.50 |
| Overall incident score = | -0.643 | ||
Score = avg(topic contributions) × significance (high ×1.5) × confidence (0.57)
Evidence (1 signal)
Microsoft issued out-of-band patches for CVE-2026-21509 Office vulnerability
Microsoft issued out-of-band security patches for a high-severity Microsoft Office zero-day vulnerability exploited in attacks, tracked as CVE-2026-21509, with a CVSS score of 7.8 out of 10.0. The vulnerability allows attackers to bypass document security checks.