CVE-2026-45498 Microsoft Defender Denial of Service
Attackers can cause a denial of service in Microsoft Defender Antimalware Platform, requiring users to apply vendor patches.
- Exploited in the wild
- Since 20 May 2026
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-45498?
CVE-2026-45498 is a medium-severity denial of service vulnerability in Microsoft Defender Antimalware Platform, published on 20 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Microsoft Defender Denial of Service Vulnerability
Weakness: CWE-400
Which versions are affected by CVE-2026-45498?
It affects 1 product.
Products include Microsoft Defender Antimalware Platform.
How do I fix CVE-2026-45498?
No fix has been published for CVE-2026-45498 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 Jun 2026.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-45498 being exploited?
Yes. Attackers have exploited CVE-2026-45498 in the wild since at least 20 May 2026.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Microsoft Defender Antimalware Platform
Sources
Also known as GHSA-8gp3-pghr-6wxp.