Learn Editor: Update microsoft-defender-antivirus-updates.md

Author: j0shbregman

defender-endpoint/microsoft-defender-antivirus-updates.md

@@ -77,7 +77,8 @@ Updates contain:
 ### September-2025 (Platform: 4.18.25090.3009 | Engine: 1.1.25090.3001)
 
 - Security intelligence update version: **1.439.345.0**
-- Release date:  **September 8, 2025 (Engine) / September 21, 2025 (Platform)**
+- Release date:  **October 8, 2025 (Engine) / October 21, 2025 (Platform)**
+
 - Platform: **4.18.25090.3009**
 - Engine: **1.1.25090.3001**
 - Support phase: **Security and Critical Updates**