Microsoft Defender (Platform)
Microsoft · current 4.18.26070.9
The current version of Microsoft Defender (Platform) is 4.18.26070.9 (as of 05/08/2026). patchletter checks the official source daily and emails you every new release.
Actively exploited vulnerabilities
The US cybersecurity agency CISA lists these vulnerabilities in its catalog of Known Exploited Vulnerabilities. Check your version and patch or mitigate promptly.
7.8 high · locally only, with a basic account · CISA deadline was 6 May
5.4 medium · over the network, without login, needs user action · CISA deadline was 3 Jan 23
- CVE-2021-1647Microsoft Defender Remote Code Execution Vulnerability
7.8 high · locally only, with a basic account · CISA deadline was 17 Nov 21
- CVE-2026-41091Microsoft Defender Link Following Vulnerability
7.8 high · locally only, with a basic account · CISA deadline was 3 Jun
- CVE-2026-45498Microsoft Defender Denial of Service Vulnerability
7.5 high · over the network, without login · CISA deadline was 3 Jun
Source: CISA KEV. The CVE is matched to the product automatically — when in doubt, the linked NVD entry applies.
Microsoft Defender (Platform) at a glance
Microsoft Defender Antivirus is built into Windows; its platform, engine and security-intelligence updates keep detection current. Microsoft ships very frequent intelligence updates plus periodic platform/engine updates, largely automatic.
For admins the day-to-day is ensuring the components stay current and healthy: intelligence updates flow through Windows Update/MDM, while platform and engine updates arrive periodically — keep the channels open. Verify that endpoints report a current platform version and that tamper protection and cloud-delivered protection are on. As the built-in AV with deep system access, its health is central to endpoint security. In managed environments, monitor Defender status centrally (Intune/MDE) so no device falls behind on definitions or platform.
Version history & changelog · as detected by patchletter
| Version | Channel | Date | Notes |
|---|---|---|---|
| 4.18.26070.9 | STABLE | 05/08/2026 | Release notes → |
| 4.18.26060.3008 | STABLE | 26/07/2026 | Release notes → |
Frequently asked questions
- What is the latest version of Microsoft Defender (Platform)?
- Microsoft Defender (Platform) 4.18.26070.9, released 05/08/2026. patchletter checks the vendor's official source daily for new releases.
- Where can I find the Microsoft Defender (Platform) release notes?
- The version history above links to the vendor's official release notes where the vendor publishes them. patchletter deliberately stores no vendor full texts.
- How do I get notified about new Microsoft Defender (Platform) updates?
- Free by email: patchletter reports every new release — instantly or bundled as a digest. Unsubscribe anytime with one click.
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[](https://patchletter.com/en/software/microsoft-defender-platform)https://patchletter.com/badge/microsoft-defender-platform.svgAlso available: ?v=eol (end of support) and ?v=cve (actively exploited).
