RECENTProduct updateAction required
Windows Antivirus | September 2026 | Platform 4.18.26090.9 | Engine 1.1.26090.9
Analysis / inference: Microsoft has released platform version 4.18.26090.9 and engine version 1.1.26090.9 for Microsoft Defender Antivirus.
- Dates
- Source and collection dates not recorded
- Source
- Microsoft Defender for Endpoint releases · Limited verification
- Classification
- Microsoft Security
Section 01 · Summary analysis
Platform version 4.18.26090.9, engine version 1.1.26090.9, and security intelligence version 1.461.1.0 have been released for Windows Antivirus.
AI summary / analysis; claims are not independently verified. Check the primary source before acting.
Section 02 · Analysis
SecOps Signal analysisWhy it matters
Keeping Microsoft Defender Antivirus platform and engine binaries up to date ensures reliable telemetry generation and threat detection ingestion into Microsoft Defender for Endpoint.
Operational impact
Endpoint agents receive standard updates for stability and threat detection capabilities without requiring manual analyst intervention unless update pipelines stall.
Section 03 · Recommended actions
- Verify endpoint update compliance through Microsoft Defender portal or configuration management tooling.
What to check
- Verify the deployed platform version matches 4.18.26090.9 across endpoints.
- Verify the engine version matches 1.1.26090.9.
- Check that security intelligence updates are applying normally beyond version 1.461.1.0.
Affected scope
ProductsDefender for Endpoint